--HAPPY DEBATE DAY: Eleven candidates are slated to be on stage for the main debate at 8 p.m. Eastern tonight at the Ronald Reagan Presidential Library hosted by CNN. The four bottom-tier candidates will be in an undercard debate at 6 p.m. Eastern. It seems likely that Ronald Reagan's rule -- never speak badly of a fellow Republican -- will be violated several times in his own presidential library. Each candidate has their work cut out for them. Here are the five things to watch for when the top Republican contenders face off, courtesy of ABC's RYAN STRUYK, KATHERINE FAULDERS, JOHN SANTUCCI, JORDYN PHELPS and CANDACE SMITH: http://abcn.ws/1gq7kRl
--TRUMP WAGES A WAR ON 10 FRONTS: It's not a question of "if" or "when" -- it's a matter of "who" will attack Trump first at the debate. He's attacked just about everyone on that stage. From Carly Fiorina's looks to Jeb Bush's energy, Trump has even warned Ben Carson not to pick a fight with the Donald. Still, Trump says has said he doesn't start fights, saying he's a "counter puncher." But with neurosurgeon Carson rising quickly behind Trump, the pressure is on.
--FIORINA STEPS INTO THE SPOTLIGHT: After a hard fought battle off the "kids' table" for a chance to play in the big leagues, Fiorina has officially earned a spot on the GOP primetime debate stage. Fiorina, who shined at Fox's "Happy Hour" debate last month, comes ready to make some noise, especially towards Trump. Even though Fiorina is an outsider, she's yet to seize on the support that Trump and Carson have seen, remaining stalled in the single digits in the polls. Expect the only woman in the packed GOP field to go after the mogul for his statements about women.
--CARSON REACHES THE MOMENT OF TRUTH: Trump vs. Carson: That's what the polls are saying. The two GOP frontrunners will be standing together center stage -- and Carson is sure to get more talking time than last go-around. Just a day before the debate, the retired neurosurgeon is surging in the polls, trailing only slightly behind the real estate mogul. Carson has repeatedly said he refuses to attack The Donald, but last week he gave in by attacking his faith.
-- SCOTT WALKER'S DO-OR-DIE MOMENT: The Wisconsin governor will take the stage acutely aware of how high the stakes are for his candidacy. Walker has seen his poll numbers diminish from solid double digits to low single digits and he's lost his title as the early frontrunner in the first-in-the-nation caucus state of Iowa. Walker has said that voters can expect to see a more aggressive and passionate candidate in the second debate.
--CAN BUSH CLAW HIS WAY BACK TO THE TOP? The second debate presents an opportunity for Bush, a chance to recover from an uninspiring performance during the last debate. But can he seize it? He's sinking in the polls, having rapidly lost his frontrunner status to political outsiders Trump and Carson. He's also been criticized for being "low-energy", opting to answer questions in his typical cerebral, wonkish style, rather than the more theatrical effect to which many credit Trump's rise in support. After many vigorous on-the-road sessions, Bush says he's ready to tout his "conservative" record as former Florida governor.
ANALYSIS -- ABC's RICK KLEIN: If you're prepping your Bingo card/drinking game, here are a few phrases that might not come through - or won't, at least, in the bigger game being played for the GOP nomination. "When I was governor" ... "I filed a bill" ... and even, "We got results." Those are the tropes and standbys of typical political years, and the 13 candidates who've held elected office are sure to try to use them again Wednesday night. But lines like those have less resonance for an electorate valuing outsiders and punishing insiders. There are things Donald Trump can be blamed for, but this isn't one of them. Trump is taking advantage of an opening, sensing the moment and yes, exploiting it. It's one of the many factors that are driving the second debate toward conflict. Many of the attacks will be aimed at the man in the middle of the stage, of course. But the candidates not named Trump remain likely to have to play as much defense around their own accomplishments as they will offense.
with ABC's PAOLA CHAVEZ and VERONICA STRACQUALURSI
TRUMP ABOARD US BATTLESHIP: 'I AM WITH THE VETERANS 100%' Republican Presidential Candidate Donald Trump said last night "We have illegal immigrants that are treated better by far than our Veterans." Speaking on board the World War II-era battleship USS Iowa in Los Angeles, Trump addressed supporters as about 200 protesters were on the shore chanting, ABC's JOHN SANTUCCI notes. One held a sign reading "no human is illegal." "We're gonna make our military so big and so strong and so great," said Trump. Trump also said he would make it his mission to reform the VA and provide better medical care to veterans. Trump was invited on board the USS Iowa by Veterans for a Strong America, who announced they're endorsing the real estate mogul. As he exited, he waved to the protesters, gave them a thumbs up as they booed and he sped away. http://abcn.ws/1gpKppq
HOW LATE IS TOO LATE FOR JOE BIDEN TO JUMP INTO 2016 RACE? Does Joe Biden need to get in before the first Democratic debate to be a viable candidate? That's a question being weighed by advisers close to the vice president as he continues to mull a potential White House bid, South Carolina state representative and longtime Biden supporter James Smith tells ABC's JORDYN PHELPS. "There's been some discussion about October and whether the first debate is critical," Smith, who has spoken to Biden advisers, said. "And my conclusion in the discussions I've had is that it's not a show stopper." Smith said "there's no sense of urgency" among the Biden's inner circle as they await his final decision, which hinges on the vice president's personal healing process following the loss of his son Beau, who died of brain cancer at the age of 46 in May. It's entirely possible that the first Democratic debate, set for Oct. 13, will come and go with the vice president still on the fence. But how long can he realistically wait before the decision is made for him? http://abcn.ws/1gqkv4I
NOTED: BIDEN GOES WEST. Vice President Joe Biden travels to California today where he'll deliver remarks at Solar Power International, a solar power trade show in Anaheim, and address the U.S.-China Climate Leaders Summit in Los Angeles, ABC's ARLETTE SAENZ notes. The vice president's visit to Southern California comes on the same day that Republican presidential candidates debate up the road in Simi Valley. While Republicans may train their sights on attacking Donald Trump on stage, the Vice President got in on the action last night, describing the real estate mogul's comments on immigration as a "sick message," one that aims at "denigrating an entire group of people." Biden may be undecided about his own presidential ambitions, but his remarks show he's willing to wade into the 2016 fight.
WHY SOME DEMOCRATS AREN'T GIVING UP ON MORE DEBATES. As Republican presidential hopefuls gather for their second nationally televised debate in California, across the country this evening a group of Democrats are planning a protest in front of the Democratic Party headquarters in Washington, D.C., over the number of debates allowed for their candidates, ABC's MARYALICE PARKS notes. Ben Doernberg, founder of a group called "Allow Debate," which is organizing the protest, said his group plans to present the Democratic National Committee with a petition signed by over 20,000 people. The DNC has sanctioned six debates this election cycle. While it is the same number the committee sanctioned in the past, unlike previously years, the DNC this time is promising to disinvite candidates who participate in non-sanctioned debates. This so called "exclusivity clause" has frustrated those who believe more debates are needed. http://abcn.ws/1W2IdnY
8 POLL NUMBERS THAT SHOW DONALD TRUMP IS FOR REAL. Some have tried to label him a flip-flopper. Others have dismissed him as a joke. And some are holding out for an implosion. But no matter how some Republicans are trying to drag Donald Trump down from atop the polls, it hasn't worked (yet). ABC'S RYAN STRUYK notes ten of the last 11 national polls have shown Donald Trump's lead at double digits, and some are starting to ask seriously what it means for the real estate mogul's nomination chances. http://abcn.ws/1F10LAE
WHY THIS GUY TRICKED OUT HIS TELSA FOR BERNIE SANDERS. Paul Sasso kicked off fall with a Bernie Sanders-inspired road trip. ABC'S MARYALICE PARKS notes, the San Diego architect, Sasso started following Bernie Sanders closely after the 2008 financial crisis, and while he hopes to raise money for the senator, the real goal is getting the word out. "It's about social media and getting people engaged. We need people to know who Bernie is," Sasso said. http://abcn.ws/1JaiC31
IN CASE YOU MISSED IT
CONSERVATIVE SUPER PAC DECLARES WAR ON DONALD TRUMP. The battle against Donald Trump is ramping up on a new front: Super PACs. ABC's MADISON JAROS and RYAN STRUYK report on the economic conservative Super PAC that is jumping into the fray, "Club for Growth Action" is unveiling an Iowa ad buy with two television spots worth more than $1 million. The ads start Thursday in Iowa, both on local television and on Fox News. http://abcn.ws/1OcH0c8
@TheBrodyFile: .@TheBrodyFile Video Exclusive: @realDonaldTrump Says He Will Try And "Tone It Down" Watch: http://blogs.cbn.com/thebrodyfile/archive/2015/09/16/brody-file-video-exclusive-donald-trump-says-he-will-try.aspx ... #CNNDebate #CBN2016
@washingtonpost: Alongside Trump's campaign, activist clashes are growing uglier http://wapo.st/1OvUAGT
@jimgeraghty: To give credit where it's due, it's nice to see a candidate spitting hot fire about the VA. http://bit.ly/1ivosHz
@rollcall: 15 years after Florida's hanging chads, dysfunctional voting machines could once again disrupt Election Day: http://roll.cl/1NuypA8