The Note: Candidates Aim for AIPAC Vote

— -- NOTABLES

--CANDIDATES GET SET TO COURT THE PRO-ISRAEL VOTE: Presidential candidates are set to take turns courting the pro-Israel vote at the American Israel Public Affairs Committee Policy Conference in Washington D.C. today. All three Republican candidates and Democratic front-runner Hillary Clinton are scheduled to speak before the group. Bernie Sanders was invited, but he is not scheduled to appear. ABC’s PAOLA CHAVEZ and VERONICA STRACQUALURSI highlight a few things to look out for today: http://abcn.ws/1MsbGSc

--RNC CHAIR ON CONTESTED CONVENTION --  ‘WE’RE PREPARING FOR THAT POSSIBILITY’: RNC Chairman Reince Priebus said he no longer thinks a contested convention is an extreme hypothetical and party officials are trying to be transparent to “take the mystery away from what an open convention looks like,” he said on ABC News' “This Week” Sunday. “I think it’s possible and we’re preparing for that possibility,” he said. If a candidate does not have the 1,237 delegates required to win the nomination outright, it sets up a contested convention, during which some delegates are freed up in subsequent rounds of voting to choose whomever they want. Priebus also addressed the Stop Trump movement, ABC’s RYAN STRUYK and NICKI ROSSOLL note, and said the possibility of running a third party candidate against Donald Trump, if he becomes the Republican nominee, would doom the chances of the Republican party winning the general election. http://abcn.ws/1ZhCko7

--ANALYSIS -- ABC’s RICK KLEIN: The thing about the plan is, there is no plan. More than halfway through the voting, with Donald Trump far and away the delegate leaders – and therefore the GOP frontrunner, and it’s not even close – the anyone-but-Trump forces are as scattered and uncertain as ever. There’s no consensus alternative, not with Ted Cruz and John Kasich both still running (and both touting support they got from the party’s most recent nominee, inside the last week). There’s no consensus on the third-party route – neither on whether to do it nor whom to do it with. There’s no firm sense that any of the tens of millions in anti-Trump spending has had its desired effect, or that future spending can hope to be successful, either. So it is that as Trump comes to Washington Monday to court the establishment, the establishment (such as it is) can agree on only one, longshot-in-itself, goal for stopping Trump: denying him a majority of convention delegates. Even that is undercut by the growing list of elected officials and party regulars boarding the Trump train. Trump’s been advising the GOP to embrace, rather than fight, the energy he’s brought to the party. That advice will sound more tempting the closer Trump gets to his magic number.

YESTERDAY ON THE TRAIL with ABC’s VERONICA STRACQUALURSI

TRUMP ADDING ADDITIONAL SECURITY TO EVENTS. Donald Trump's campaign said Sunday it is beefing up security, after a string of protests and violence at the Republican presidential candidate’s events. "We will be dedicating additional security resources to larger events in the future to prevent staff from having to intervene,” campaign spokeswoman Hope Hicks said in a statement to ABC News. The statement comes the day after an incident involving Trump campaign manager Corey Lewandowski at a campaign event in Tucson, Arizona, that was captured on video, according to ABC’s CANDACE SMITH. http://abcn.ws/1WBeVw8

NOTED: MAN CHARGED WITH ALLEGEDLY PUNCHING AND KICKING ANTI-TRUMP PROTESTER AT RALLY. A man captured on video punching and kicking a protester at a Donald Trump rally in Tucson, Arizona, was charged with assault with injury, police said. The man, identified as Tony Pettway, 32, was arrested inside the Trump event and charged with the misdemeanor before being released, the Tucson Police Department said. ABC’s KATHERINE FAULDERS and DAVID CAPLAN have more: http://abcn.ws/1nYM3Sz

RNC CHAIR ON TRUMP RALLY VIOLENCE: ‘LEAVE IT TO THE PROFESSIONALS.’ Republican National Committee Chairman Reince Priebus says Trump supporters should “leave it to the professionals” when it comes to quelling interruptions, ABC’s RYAN STRUYK notes. http://abcn.ws/1puSXQD

TRUMP CAMPAIGN DENIES CAMPAIGN MANAGER COREY LEWANDOWSKI GRABBED PROTESTER. The Trump Campaign is pushing back against video that appears to show campaign manager Corey Lewandowski grabbing the collar of a protester during a rally in Tucson, Arizona Saturday night. The video, first posted by CBS News and then by CNN with a clearer angle, shows a male protester yanked backwards while attempts were being made to eject him from the event. The protester, reacting to the grab, appears to begin to push the man to Lewandowski’s left. He was ultimately escorted out of the event. The Trump campaign instead blamed the incident on a different man, who also appears to be yanking the collar of the protester simultaneously with Lewandowski, ABC’s KATHERINE FAULDERS reports. http://abcn.ws/1T3q3Dl

BERNIE SANDERS DEFENDS STAYING IN THE RACE. Bernie Sanders argued Saturday that Democratic voters would be less likely to participate in the general election if the primary race concluded early, resisting any suggestion he should drop out of the chase for the Democratic Party's presidential nomination. "If you say that half the states in this country -- that they should not participate -- their response may well be on Election Day, 'You didn't want us to participate in the primary process, you know, we are not going to come out for the general election," Sanders told reporters while campaigning in southern Arizona ahead of its primary. Sanders reiterated his determination to stay in the race, despite losing to Hillary Clinton in all five states that voted this week past, ABC’s MARYALICE PARKS writes. He again noted that large states such as California and New York, as well as other West Coast states like Washington and Oregon where the campaign believes he will do well, still have not had their say. http://abcn.ws/1Us13Xn

IN CASE YOU MISSED IT

TRUMP TWEETS THAT CUBAN LEADER RAUL CASTRO HAS ‘NO RESPECT’ FOR PRESIDENT OBAMA. President Obama and his family arrived in Cuba Sunday for a two-and-a-half-day trip, and it didn’t take long for Republican critics to get busy. Donald Trump noted almost immediately that Cuban President Raul Castro was not on the airport tarmac to greet the first family. The Republican front-runner tweeted Sunday that Castro greeted Pope Francis on his arrival in Cuba last month, adding that el presidente had “no respect” for Obama. Meanwhile, according to ABC’s VERONICA STRACQUALURSI, Sen. Ted Cruz said Obama’s trip is “injurious to [America’s] future as well as Cuba’s” and that the result of the trip will “not be liberalization but rather the institutionalization of the Communist dictatorship.” http://abcn.ws/1o1hV9l

WHO’S TWEETING?

@costareports: Anti-Trump super PACs are planning to stake out Trump mtg in DC on Monday to get tracker footage of Rs who attend, per sources

@ByronYork: Why are many of Ryan's Republicans silent about Trump? Well, it could be because he's winning their districts. http://ow.ly/ZKlEY 

@EliStokols: Amidst swirl of protest, Trump plans to deliver a 'presidential' speech at AIPAC Monday. http://www.politico.com/story/2016/03/trump-aipac-israel-protests-221002 …

@brikeilarcnn: AIPAC leadership: we've invited candidates we don't necessarily agree w/on substance or tone. Clap if you agree w/them, don't if you don't.

‏@HeidiPrzybyla: Former NYT editor Jill Abramson, after her own ouster, on @HillaryClinton: ‘She does get more scrutiny’ than men http://www.politico.com/story/2016/03/jill-abramson-hillary-clinton-2016-221017 …