Olivier Douliery-Pool/Getty Images

By MICHAEL FALCONE ( @michaelpfalcone )

NOTABLES

• NEWTOWN FAMILIES HEAD TO THE HILL: With a filibuster threat in the air, the gun control debate takes a personal turn today on Capitol Hill as the families of the Newtown shooting implore members of Congress to revive legislation that has stalled nearly four months after the slaying at Sandy Hook elementary school, reports ABC's JEFF ZELENY. A group of mothers and fathers of the victims came to Washington aboard Air Force One after President Obama sought to rally support for the gun control bills during a speech Monday in Connecticut. It is an effort by the White House to regain momentum for the gun measures. "Find out where your member of Congress stands on this," Obama said yesterday. "If they're not part of the 90 percent of Americans who agree on background checks, then ask them why not."

• CAN THEY COMPROMISE?: ZELENY notes that Senate Majority Leader Harry Reid, Democrat of Nevada, has set a tentative deadline of later today for a compromise deal to be brokered on a key piece of the legislation on background checks. If an agreement is not reached, aides said, he will begin scheduling votes on the bills later this week. Two senators - Joe Manchin, a West Virginia Democrat, and Pat Toomey, a Republican from Pennsylvania - are working on a possible bipartisan compromise on background checks. The plan would allow close friends and family to be excluded from those background checks if they are selling or trading guns to each other. But no formal meeting has yet been scheduled today between the two senators, aides tell ABC News, and it remains an open question if they will be able to come to an agreement that would have to gain support from at least 60 senators to move beyond a filibuster. http://abcn.ws/Z5wklh

• DEMOCRATS CALL MCCONNELL 'WASHINGTON'S TOP ROADBLOCK': A pro-Democratic super PAC unveiled an online campaign on Tuesday that aims to draw attention to what the group says is Senate Minority Leader Mitch McConnell's "record of putting Washington's interests above Kentucky's." ABC's MICHAEL FALCONE reports that the Senate Majority PAC has created a microsite, "Beltway Mitch," that calls the Kentucky senator, who is up for re-election in 2014, "Washington's top road block" and accuses him of being "deep in hock to extreme special interests." "As a top Washington insider, Mitch McConnell has left Kentuckians' interest behind and voters need to know his true record," Rebecca Lambe, co-chair of the Senate Majority PAC said in a statement. In addition to the website, officials with the group said its anti-McConnell push would also include paid content on social media sites such as Facebook and Twitter. So far, no top Kentucky Democrats have launched a bid to challenge McConnell, leaving it to organizations like the Senate Majority PAC and the Democratic Senatorial Campaign Committee to start chipping away at McConnell's record as they try to damage his hopes of winning a sixth term. http://abcn.ws/YaeqKL

THE ROUNDTABLE

ABC's RICK KLEIN: Watch the left, again. President Obama is looking for a game-changer on his budget, to send a signal that he's serious about breaking the cycle of conflict on spending and debt. But his proposals to trim the growth of Social Security and Medicare have his own teammates questioning his strategy and leadership - and the budget won't even be introduced until tomorrow. Maybe this will be the only path to progress with Republicans (if Bernie Sanders loves the budget, John Boehner and Eric Cantor won't come to that particular table). But it complicates the president's political position as deficit discussions start to fire up again. Just about every previous possible grand bargain was predicated on Democrats providing at least half the votes. The president's own party has to be comfortable for any set of talks to be worth the time.

ABC's DEVIN DWYER: With all the attention on a bipartisan breakthrough on immigration, it's easy to lose sight of the opposition. But foes of a so-called "amnesty" for 11 million undocumented are marshalling forces to pounce on a draft "Gang of Eight" reform bill when it's released. "We just passed the 1.7 million member mark. Now we are growing by about 15,000 a day," NumbersUSA president Roy Beck told ABC News. "Once there's actually a bill with the details we will start to see this sense of inevitability [about its passage] melt away." In the sights of activists: red-state Senate Democrats up for re-election in 2014. "We've done polling. We know that the people in their states absolutely hate the idea of giving up those work permits to millions of illegal aliens," Beck said. "Those Democrats are going to have a hard time voting for this." The tested economic message is already appearing in TV ads against two Senators, including Democrat Mark Begich of Alaska. This spot accuses him of a plan to "bring in foreign workers to take Alaska jobs." WATCH: http://bit.ly/YeA9pk

ABC's SHUSHANNAH WALSHE: Former Congresswoman Gabby Giffords and her husband Mark Kelly have become the public faces spearheading the fight for universal background checks. They will travel to Washington, DC to press members of Congress in person next week. In an interview with ABC News' Jonathan Karl on Monday Kelly said, "failure is not an option" and "Gabby will be incredibly disappointed, as I imagine a large part of this country will be, if a universal background check bill is not passed here in this session." Kelly warned that if Congress does not act, there will be political consequences: "I think come the 2014 elections I think people are going to remember that, assuming nothing happens here, that in 2014 they will remember that Congress failed to support something that nearly 100 percent of Americans wanted to happen." Today several of the Sandy Hook families will be meeting with members of Congress also in order to put a public face on a grief as they advocate for stricter gun controls. Nevertheless, Washington is once again awash in talk of a filibuster - this time on the gun measures. More of Mark Kelly's interview with ABC's JONATHAN KARL: http://abcn.ws/10OsLNe

IN THE NOTE'S INBOX

-EMILY'S LIST PUTS SIX CONGRESSMAN 'ON NOTICE.' The pro-Democratic group, Emily's List, today added six members of Congress to its infamous "on notice" list. The group notes that Joe Heck, R-Nev., John Kline, R-Minn., Tom Latham, R-Iowa, Tom Reed, R-N.Y., Scott Tipton, R-Colo., and David Valadao, R-Calif., all "meet two special criteria: First, they've amassed appallingly anti-woman, anti-family records. And second, there is major Democratic female talent waiting in the wings." Emily's List President Stephanie Schriock said in a statement, "Representatives Heck, Kline, Latham, Reed, Tipton, and Valadao have a record - in some cases years long - of voting for some of the most shocking anti-woman legislation in the country. Each one of them has proven there's no limit to how far they'll go to roll back the clock." http://emilyslist.org/on_notice

-RALPH REED JOINS BLOOMBERG-BACKED PRO-IMMIGRATION PUSH. An announcement from New York Mayor Michael Bloomberg's group, the Partnership for a New American Economy, which is advocating for immigration reform: "Faith and Freedom Coalition founder Ralph Reed, City of Doral Mayor Luigi Boria, President of the Pastors Association of Greater Miami, Dr. Alberto Delgado, and other religious leaders and social conservatives from Miami will hold a press conference Tuesday, April 9, to urge Congress to act on bipartisan comprehensive immigration reform." The event takes place at Ekklesia Global in Miami, Fla. at 11 a.m. ET.

-KEN CUCCINELLI'S CAMPAIGN ATTACKS TERRY MCAULLIFE OVER GREENTECH. Virginia gubernatorial candidate Ken Cuccinelli's campaign is out with a new web video today hitting Democratic opponent Terry McAuliffe over his relationship to an automotive company he started called GreenTech. McAuliffe has encountered criticism after news of his quiet departure from the company surfaced last week. WATCH: http://bit.ly/Xp15AU

BUZZ

REID CALLS REPUBLICANS 'AFRAID' OF GUN DEBATE. Senate Majority Leader Harry Reid, D-Nev., had some tough words for Republicans threatening to filibuster gun control legislation the full Senate will start working on this week: "Shame on them." "Senate Republicans seem afraid to even engage in this debate," Reid said yesterday on the Senate floor of the Republicans threatening to filibuster the gun control legislation, according to ABC's SUNLEN MILLER. "The least Republicans owe the parents of these 20 little babies who are murdered at Sandy Hook is a thoughtful debate about who whether stronger laws could have saved their little girls and boys," Reid said. "The least Republicans owe them is a vote." In late March, three Republican senators - Rand Paul of Kentucky, Ted Cruz of Texas and Mike Lee of Utah - sent Reid a letter threatening to filibuster the gun control legislation. The letter yesterday morning was re-delivered with a little more weight to it, with now 13 Republican signers, including Senators James Inhofe of Oklahoma, Richard Burr of North Carolina, Mike Enzi of Wyoming, Marco Rubio of Florida, Jerry Moran and Pat Roberts of Kansas, Ron Johnson of Wisconsin, Dan Coats of Indiana, and Mike Crapo and James Risch of Idaho. http://abcn.ws/17noXZW

ILLINOIS HOLDS SPECIAL ELECTION TO FILL JESSE JACKSON JR. SEAT. Voters in Illinois go to the polls today in a special election to fill former Rep. Jesse Jackson Jr.'s Chicago-based seat, ABC's RICK KLEIN notes. After Tuesday night, Illinois' Second Congressional District will almost certainly be represented by Democratic nominee Robin Kelly, a former state representative who is now Cook County's chief administrative officer. Kelly's elevation to Congress - she faces Republican Paul McKinley in the extremely blue district - will shine a spotlight on the politics of gun control. Kelly made her support for stricter gun-control measures a major issue in the Democratic primary, earning her the support (and financial backing) of New York City Mayor Michael Bloomberg. The president cited Kelly's support for gun control in issuing his endorsement after the primary, which of course is taking place in the president's hometown, as Chicago deals with a rash of gun violence.

CHELSEA CLINTON RE-OPENS DOOR TO POLITICS. Chelsea Clinton, the only child of former Secretary of State Hillary Clinton and former President Bill Clinton, is again opening the door to entering politics herself one day, ABC's SHUSHANNAH WALSHE notes. "Right now I'm grateful to live in a city, in a state and a country where I strongly support my mayor, my governor, my president, my senators and my representative," Clinton said on NBC's "Today" show Monday. "If at some point that weren't true and I thought I could make a meaningful and measurably greater impact, I'd have to ask and answer that question." Clinton is a special correspondent for NBC News. This is just the latest flirtation with entering elected politics. In an interview this weekend with Parade Magazine she gave a similar answer saying she doesn't know if she will, but she is "grateful to live in a city, in a state, in a country where I strongly believe in the confidence and ethos of my direct elected representatives," but "if there were a time where that wasn't true and I thought that I could make a disproportionately positive impact, I'd have to ask and answer that question."

DID OFFICERS THWART SHOOTING AT CAPITOL? As thousands of tourists packed the National Mall this weekend, Ty Carroll Mitchum parked his vehicle on Capitol Hill Sunday, drawing suspicion as he wandered around the U.S. Capitol grounds muttering to himself. His behavior caught the attention U.S. Capitol Police, who discovered three unregistered firearms and more than 100 rounds of ammunition in his vehicle. According to the charging document, Mitchum possessed a Remington 12 Gauge Shotgun Model 870, a Springfield Armory 9MM handgun Model DX9, and a Smith and Wesson 38 caliber revolver. He also had 69 rounds of 9mm ammunition, as well as 38 rounds of 44 caliber bullets. It's unclear whether any of the firearms were loaded. Sources say Mitchum did not threaten anyone with the firearms and law enforcement officials downplayed the incident, pointing to other routine stops this year that have yielded unregistered firearms near the Capitol. But with the spotlight on Congress this week as it begins debating new gun control measures, this arrest seems to stand out among the routine incidents. ABC's JOHN PARKINSON has the backstory: http://abcn.ws/12Cggr0

SEQUESTER MIGHT DELAY TRIAL FOR 9/11 SUSPECT. Sequestration budget cuts could stand between Osama bin Laden's son-in-law, Suleiman Abu Gaith, and a trial on American soil timed almost to match up with the anniversary of the September 11 attacks, reports ABC's SARAH PARNASS. Judge Lewis Kaplan yesterday said Abu Gaith could go on trial in federal court in Manhattan as early as September of this year, around the anniversary of the 9/11 attacks the suspect lauded in al-Qaeda videos. Gaith's lawyer protested, saying a September start might be too soon, because of sequester cuts to public defenders. The judge said it would be unfortunate if sequestration issues interfered with a trial of this importance, and he agreed to appoint other lawyers to assist the federal defenders service. The U.S. court system stands to lose almost $350 million to sequester cuts. Last month Judge Julia Gibbons, chair of the Judicial Conference Budget Committee, testified that leaving sequestration as is would "have a devastating effect on federal court operations nationwide." http://abcn.ws/10BCTvF

WHAT WE'RE READING

"MICHAEL BLOOMBERG GROUP'S GUN-CONTROL SCORECARD WILL GIVE LAWMAKERS LETTER GRADES," by the Washington Post's Philip Rucker. "New York Mayor Michael R. Bloomberg, one of the nation's most committed and deep-pocketed gun-control proponents, is ratcheting up pressure on lawmakers by launching a new system to grade them based on their votes and statements on gun issues. Mayors Against Illegal Guns, the nonprofit group financed by Bloomberg (I), will unveil a scoring system Tuesday to award lawmakers grades of A through F, much like the National Rifle Association, which has derived much of its power by deploying letter rankings against politicians at election time. The group's strategists briefed The Washington Post on the plans ahead of Tuesday's announcement. … Mayors Against Illegal Guns will start airing a 60-second ad on Tuesday featuring Neil Heslin, whose son, Jesse Lewis, was killed in December's elementary school massacre in Newtown, Conn. The group is spending more than $1 million to air the ad on cable news in Washington and on television stations in 10 targeted states, officials said. The group is targeting Sens. Saxby Chambliss (R-Ga.), Daniel Coats (R-Ind.),Joe Donnelly (D-Ind.), Jeff Flake (R-Ariz.),Kay Hagan (D-N.C.), Heidi Heitkamp (D-N.D.), Dean Heller (R-Nev.), Johnny Isakson (R-Ga.), Mary Landrieu (D-La.),Rob Portman (R-Ohio), Mark Pryor (D-Ark.) and Patrick J. Toomey (R-Pa.)." http://wapo.st/Xp658T

WHO'S TWEETING?

@DavidCornDC: Secret Tape: McConnell and Aides Weighed Using Judd's Mental Health and Religious Views as Political Ammo http://www.motherjones.com/politics/2013/04/mitch-mcconnell-ashley-judd-secret-tape-senate …

@timkaine: I'm ready to vote yes on limits on combat weapons & universal background checks. Read my op-ed in the @PilotNews http://hamptonroads.com/2013/04/let-senate-vote-gun-measures …

@mikememoli: Republicans reach out to Asian American voters with new hires http://lat.ms/10E5Kzx

@ezraklein: Will Max Baucus undermine Democrats on taxes? http://wapo.st/10Os1tg

@robertcostaNRO: @KatrinaTrinko reports: Scott Brown is seriously eyeing a NH Senate run http://www.nationalreview.com/articles/345060/scott-browns-next-move-katrina-trinko …