By MICHAEL FALCONE ( @michaelpfalcone ) and AMY WALTER ( @amyewalter )

NOTABLES:

• CHRIS CHRISTIE TO KEYNOTE GOP CONVENTION. After the New York Post reported in July that he would fill the keynote slot at the GOP convention in Tampa, the plan is now official. The New Jersey governor tells USA Today: "I'll try to tell some very direct and hard truths to people in the country about the trouble that we're in and the fact that fixing those problems is not going to be easy for any of them." Republican National Committee Chairman Reince Priebus announced Christie's keynote slot Tuesday morning, saying, "He is a leader of principle and conviction, and I am excited to hear him address the Republican National Convention as our keynote speaker." http://usat.ly/QZIJTB

• RUBIO TO INTRODUCE ROMNEY AT RNC. Tampa Bay Times' Richard Danielson reports: "In a showcase role on his party's biggest stage, Florida Sen. Marco Rubio will introduce Mitt Romney for his speech to accept the nomination for president on the last night of the Republican National Convention. It is an introduction aimed at giving Romney a boost from a rising star in a must-win state, but it will almost certainly further enhance Rubio's standing, too. … On Monday in Miami, he introduced Romney, who in turn mentioned Rubio as much as Ryan, getting big cheers when he did. On Wednesday, Rubio will go to Texas to help raise money for Romney." http://bit.ly/Pgxwgn

• DIANE SAWYER SITS DOWN WITH BOB WOODWARD. ABC's Diane Sawyer will speak with Bob Woodward in an exclusive interview about his much anticipated book, "The Price of Politics." Woodward's reporting provides a sweeping you-are-there account of how President Obama and the highest profile Republican and Democratic leaders in the United States Congress attempted to restore the American economy and improve the federal government's fiscal condition. Sawyer's interview will begin airing on "World News" on Sept. 10 and the extended interview will air later that night on "Nightline." Portions of the interview will be released Monday afternoon as part of the ABC News-Yahoo! News "Newsmakers" video series. On Sept. 11 , Woodward will sit down with George Stephanopoulos for his first live television interview on "Good Morning America." Woodward's "The Price of Politics" will be published by Simon & Schuster on Sept. 11.

THE NOTE:

This week was always going to be all about Paul Ryan - and the Romney campaign knew that.

So, it's telling that the presumptive Republican nominee avoided specifics when asked - not once, not twice, but three times - whether there are parts of Ryan's Medicare plan he disagrees with.

"Well, the items that we agree on I think outweigh any differences there may be," Romney said at a news conference in Miami. "We haven't gone through piece by piece and said, 'Oh, here's a place where there's a difference.'" http://abcn.ws/RaY99S

And Ryan, in his first solo appearance as the vice presidential candidate in Iowa yesterday did not mention the word "Medicare" once, as the Washington Examiner's Byron York notes.

"Ryan's speech was an early indicator that the Romney campaign will not go out of its way to showcase the project to which Ryan has devoted the last few years of his professional life," York writes. "[We] might see a campaign in which both Republican candidates seek to downplay their signature achievements - Romney downplaying his Massachusetts universal health care program, and Ryan downplaying the Ryan budget." http://bit.ly/QZQY1Z

But, at the end of the day, Mitt Romney's biggest challenge remains defining himself.

His unfavorable ratings are uncomfortably high for August, and even GOP strategists concede that the summer pounding by Team Obama has taken a toll on his standing in battleground states like Ohio, Florida and Virginia.

The Republican National Convention gives him his big opportunity for that reset. But, his latest assault on Obama's welfare policy has also struck a nerve. Witness the very forceful pushback from Team Obama about the ads.

As ABC's Devin Dwyer reports, the Obama campaign is out with new web video this morning pushing back on Romney's welfare attack and his "high-road lip service" in recent interviews. Fact-checkers have called Romney's claims that President Obama is ending the work requirement for welfare "pants on fire" false.

In the battle for white, working class women (a.k.a. "waitress moms") this issue has serious resonance. And, it could be a potent rejoinder to the "Mediscare" attacks by Democrats.

NOTE IT!

ABC's AMY WALTER: Remember when we all said that once the VP was picked it would limit Romney's opportunities to use these potential running mates as surrogates? Well, maybe not. Sen. Marco Rubio joined Romney on the trail in Florida yesterday (and will introduce him at the RNC in two weeks). Sen. Rob Portman is with Romney in Ohio. And, of course, Gov. Chris Christie will keynote his convention. It's also another reminder of the deep bench Republicans have in 2016.

ABC's RICK KLEIN: Among those worried about the political potency of Paul Ryan's Medicare plans - and not in a good way: Mitt Romney. By saying "there may be" differences between his plan and Ryan's, and leading with an attack on President Obama for daring to cut Medicare, Romney is intentionally muddling the entitlement message for voters. But with that goes hopes of the adult conversation about the future of government spending - the arguments that Ryan rose to national prominence making. Why have Ryan on the ticket if not for the plans he's been out front on?

ABC's JAKE TAPPER: P AUL RYAN, OBAMA'S IDEOLOGICAL NEMESIS. ABC's Jake Tapper reports for 'World News': In no small way, Mitt Romney has selected as his running mate President Obama's ideological nemesis. Now President Obama has never directly, person to person, squabbled with Mitt Romney, but he sure has with Paul Ryan. President Obama's real feelings about his ideological foe … were caught by a hot microphone at a fundraiser last year. The president privately sneered at Ryan claiming the mantle of fiscal responsibility … their public back and forth hasn't been much nicer. http://abcn.ws/TBHEkH

CAUTION: BEWARE POLLS. Stuart Rothenberg warns about sampling in recent Fox News and New York Times/Quinnipiac state polls on the presidential race: "A sample that seems disproportionately Democratic based on recent elections, as was the case with the Quinnipiac's Florida poll, or disproportionately Republican, as with Quinnipiac's Colorado poll, will produce results that should raise eyebrows … The weighted Quinnipiac sample in Florida was 36 percent Democrat and only 27 percent Republican-a dramatic shift from the unweighted numbers and a partisan mix that doesn't come close to resembling the '08 and '10 Florida electorates, and, I would argue, is unlikely to reflect the electorate in November." http://bit.ly/ShtaUt

FIRST PAID HIT ON RYAN AND MEDICARE. The labor group Workers' Voice will be running a paid campaign hitting Paul Ryan's Medicare reforms, in a series of Web ads in Nevada targeted at seniors. The group will spend $50,000 on them and will send protesters to demonstrate outside Ryan events. And as Mitt Romney campaigns on coal in Ohio today, the group will send out a mailer in which AFL-CIO President Richard Trumka accuses Romney and congressional Republicans of letting coal miners die of black lung.

THE BUZZ:

with ABC's Chris Good ( @c_good)

ABC VIDEO: RYAN HECKLED WHILE CAMPAIGNING SOLO. ABC's Jonathan Karl reports: At the Iowa State Fair today, he found excited supporters and a few loud and persistent hecklers. We were right in the middle of it all. The hecklers had come disguised as Romney supporters, complete with Romney signs. http://abcn.ws/NwhTPY

TIM PAWLENTY SAT ON THE SECRET. ABC's Shushannah Walshe reports: Tim Pawlenty was passed over as a presidential running mate twice. But to a reporter sitting on his front lawn during what must have been a difficult time - getting passed over to be Mitt Romney's running mate and not being able to tell anyone about it - he was a nice guy and a gentleman. I spent 11 days on a veepstakes watch with the former Minnesota governor. From the front seat of my rental car, I watched him walk his dog, encountered a dance team practicing on his front lawn and was even offered an ice cold beer from the man known as T-Paw. http://abcn.ws/MtZ7uZ

WISCONSIN PRIMARY TODAY. In yet another vote for Paul Ryan's election-weary home state, Wisconsinites will choose between four Republican candidates for Senate, the winner of which will run against Democratic U.S. Rep. Tammy Baldwin in November. Polls have shown former governor and Health and Human Services Secretary Tommy Thompson and financial businessman Eric Hovde in the lead.

WI-SEN: RYAN'S BUDGET ORTHODOXY ON DISPLAY. When Paul Ryan released his 2011 budget, some Republicans kept it at arm's length. How do they feel about his budget now? Look no further than the Wisconsin primary, where the top candidates have lavished praise on it and, in one case, aired radio ads celebrating its passage through the House-reminding us that in primaries and competitive races across the country, Republicans like Ryan's plan. http://abcn.ws/P9MJ3e

MEET MRS. RYAN. From The Washington Post's Krissah Thompson: "Paul Ryan's wife - a former tax attorney, lobbyist and congressional staffer with degrees from Wellesley College and George Washington University Law School - is taking careful first steps into the harsh spotlight that comes with a run for the White House. … 'You know, he's pretty low-maintenance,' said Janna Ryan [in an interview with People magazine], who is now a stay-at-home mom. "Paul is someone who goes with the flow and has one of the sunniest demeanors and most positive outlooks of anyone I've ever met. So I'd say Mitt'll probably have a lot of fun with him.'" http://wapo.st/Ph40bR

ROMNEY WON'T SAY WHERE HE AND RYAN DIFFER ON MEDICARE. ABC's Emily Friedman reports from Miami: Asked three times today whether there are parts of Rep. Paul Ryan's Medicare plan with which he disagrees, Mitt Romney offered no specifics, saying only that "there may be." "Well, the items that we agree on I think outweigh any differences there may be," Romney said of his running mate's Medicare overhaul plan at a news conference on the tarmac of the Miami airport. "We haven't gone through piece by piece and said, 'Oh, here's a place where there's a difference.'" http://abcn.ws/OW9B3w

RYAN'S PLAN: SAME CUTS AS 'OBAMCARE.' Mitt Romney and Paul Ryan have blasted President Obama for trimming $700 billion from projected Medicare spending over 10 years to fund other parts of his health care legislation. But Boston Globe health columnist John E. McDonough points out that Ryan's budget includes the same savings: "Nearly every House and Senate Republican votes for the Ryan proposal. In the spring of 2012, Ryan again releases the plan, and includes the same repeal of the ACA, minus the Medicare reductions, now approaching $700B. And, again, nearly every House Republican votes for the plan." http://bo.st/QxzoOO

DOWN-TICKET TROUBLE? The Hill's Cameron Joseph and Alexandra Jaffe report: "Republicans strategists are worried that Rep. Paul Ryan's (R-Wis.) addition to the presidential ticket will cost their party House and Senate seats this fall. Their concern: Democrats will successfully demonize Ryan's budget plan, which contains controversial spending cuts and changes to Medicare. 'There are a lot races that are close to the line we're not going to win now because they're going to battle out who's going to kill grandma first, ObamaCare or Paul Ryan's budget,' said one Republican strategist who works on congressional races." http://bit.ly/OqEX6h

GOP TICKET BROMANCE. The New York Times' Michael Barbaro reports: "The most intriguing dimension of the Romney-Ryan partnership is the unmistakable sense that the two men thoroughly enjoy each other's company. During the first 48 hours as the Republican ticket, they often seemed like a pair of long-lost, hyper-earnest, spreadsheet-loving cousins. They rarely left each other's sight, exchanging hugs, backslaps and knowing smiles, as if they knew their time together might be short-lived." http://nyti.ms/RQ3F0Q

RYAN'S JOURNEY FROM BIG SPENDER TO FISCAL HAWK. The Washington Post's David A. Farenthold reports: "For more than half his career, Ryan was a dutiful GOP foot soldier, which meant he voted for many of the budget-busting, Bush-era measures that tea partiers have come to hate. Ryan was a "yes" for expanding Medicare prescription-drug coverage, as well as bailing out the financial sector and automakers. Then, in recent years, Ryan recast himself as a GOP visionary: instead of seeking compromises with Democrats, he sketched out uncompromised GOP ideals on Medicare and Social Security. During more than 13 years in Congress, Ryan has passed just two of his bills into law." http://wapo.st/MtYmlu

PAUL RYAN BOOK CLUB: SHRUGGING OFF AYN RAND? ABC's Gregory Krieg reports: Ryan, you see, is the country's most powerful Randian. At least, he used to be. … "I grew up reading Ayn Rand and it taught me quite a bit about who I am and what my value systems are," he told [The Atlas Society]. "It's inspired me so much that it's required reading in my office for all my interns and my staff." Ryan has since denied making his staff read the books. … And in an interview with the National Review this April, he did a pretty firm about-face: "'I reject her philosophy,' Ryan says firmly. 'It's an atheist philosophy.'" http://abcn.ws/PgRpFx

ERSKINE BOWLES HEARTS PAUL RYAN. ABC's Jake Tapper reports on a video clip of Erskine Bowles, the former chief of staff to president Bill Clinton who co-chaired President Obama's fiscal commission, speaking in 2011: " … [Paul Ryan] is honest, he is straightforward, he is sincere. And the budget that he came forward with is just like Paul Ryan. It is a sensible, straightforward, serious budget and it cut the budget deficit just like we did, by $4 trillion … "The President came out with his own plan and the President as you remember, came out with a budget and I don't think anybody took that budget very seriously. The Senate voted against it 97 to nothing." http://abcn.ws/NxLPxb

ROMNEY'S NEW AIDE CRITICIZED RYAN'S SOCIAL SECURITY PLAN. BuzzFeed's Andrew Kaczynski reports: "Peter Wehner, a former aide to President George W. Bush announced he was joining the Romney campaign as a senior adviser today in an email obtained by BuzzFeed. Complicating Wehner's new role could be his past critique of entitlement reform proposals from Romney's running mate Paul Ryan. … In a leaked White House memo taking issues with Ryan's [2005 Social Security] plan, Wehner blasted the plan as irresponsible for not providing a significant enough overhaul to fix the program, but merely provided 'personal retirement accounts' alone." http://bit.ly/P9R06V

REP. JESSE JACKSON, JR. TREATED FOR BIPOLAR DISORDER. ABC's Matthew Jaffe reports: Rep. Jesse Jackson Jr. is undergoing treatment for bipolar disorder, doctors at the Mayo Clinic in Minnesota announced Monday. According to a statement from the clinic, Jackson "is responding well to the treatment and regaining his strength." The announcement by the clinic comes two months after Jackson, the son of civil rights leader Jesse Jackson, abruptly left Congress. http://abcn.ws/PgxJA6

OBAMA AT IOWA STATE FAIR: FOUR MORE BEERS! ABC's Mary Bruce and Devin Dwyer report from Oskaloosa, Iowa: Hours after Rep. Paul Ryan received a rowdy reception at the State Fair, President Obama stopped by for pork on a stick, beer and the chance to reclaim some of the Iowa support that propelled him to the presidency in 2008. … When he made it to the beer stand, Obama pronounced "Bud Lights all around on me," to cheers and laughter from the crowd. After checking his wallet, he offered to buy 10 beers for 10 people and chants of "Four More Years" quickly morphed into a chorus of "Four More Beers." http://abcn.ws/Qxxbmp

OBAMA HIGHLIGHTS DROUGHT AID. ABC's Mary Bruce reports from Boone, Iowa: Touring drought-stricken Iowa, President Obama today showcased the power of incumbency as he touted his administration's response to the drought and announced new federal aid to help farmers and ranchers. The federal government is buying up to $170 million worth of meat, poultry and farm-raised fish, the Obama administration announced this morning. "Because of the drought, there are a lot of folks out there that are trying to sell meat right now," Obama later told reporters while visiting the parched McIntosh family farm in Missouri Valley. http://abcn.ws/PTDW19

MICHELLE'S SIDE OF THE KISS-CAM STORY. ABC's Mary Bruce reports: In an interview with NBC's "The Tonight Show," the first lady told Jay Leno that she did not realize they had missed the chance to smooch. … Her daughter was quick to point out their error. "Malia came over after we got booed for not kissing. And she was she was just disgusted with us," the first lady said laughing. "She said, 'Why didn't you kiss?' And I was like, 'Kiss what? What are you talking about?' She's like, 'You were on the kiss cam. You were supposed to kiss.' And I was- we were like-we were not paying attention," she recounted. http://abcn.ws/NAeIFu

WHO'S TWEETING?

@jimgeraghty: Michael Gerson reminds us the Democrats thought the Ryan plan's "radicalism" was going to save them in 2010, too.

@stephenfhayes: So serious people are urging Mitt Romney to run away from Paul Ryan and his ideas? #absurd

JakeSherman: Boehner is doing an eye-popping 47 events in 13 states between Aug 4 and GOP convention in Tampa. 2 events each day. http://politi.co/Mu1cXU

@jestei: Good @adamnagourney piece explains Medicare issue, has voters not just pols & demonstrates the race turned to substance http://nyti.ms/RQ9oDZ

POLITICAL RADAR

-Mitt Romney campaigns in Ohio.

-President Obama campaigns in Iowa.

ABC's Josh Haskell ( @HaskellBuzz)

Check out The Note's Futures Calendar : http://abcn.ws/ZI9gV