2016 Election Forecast: Predict Which Candidate Will Win the Presidential Election

A candidate needs 270 electoral votes out of 538 to win the presidency. Get started to make your own forecast.

1.

Primary Day in Arizona and Florida

Today is a big day on the primary calendar – with Sens. John McCain and Marco Rubio on the ballot against populist upstarts. In Arizona, tea partier Kelli Ward has questioned the health and conservative credentials of the 80-year-old McCain, a two-time presidential candidate. Meanwhile, developer Carlos Beruff – who has been called the "little Trump of Florida" – is challenging Rubio from the right. Both senators are heavily favored to win, ABC's ADAM KELSEY and BENJAMIN SIEGEL note, but their margins will be an indication of the strength (or lack thereof) of the establishment.

2.

Democrats Face Down Populists in Florida

On the Democratic side, former DNC chairwoman Debbie Wasserman Schultz is fighting off progressive favorite Tim Canova, a law professor endorsed by Bernie Sanders whose campaign is well-funded. In the Senate race, Rep. Patrick Murphy is the establishment's choice, riding high on endorsements from President Obama and VP Joe Biden. He's being challenged by Rep. Alan Grayson, a progressive who is running under the cloud of an ethics scandal. Wasserman Schultz and Murphy are expected to win, ABC's ADAM KELSEY and BENJAMIN SIEGEL write.

3.

Analysis -- ABC's Rick Klein

Donald Trump's coattails get a dual test on Tuesday, with Trump-style candidates taking on incumbent Republican senators with national profiles in Arizona and Florida. Both John McCain and Marco Rubio have endorsed Trump's candidacy, despite personal insults the candidate himself has hurled their way. Trump has returned the favors, at least publicly. But Trump's broader message has resonated in the primaries in both races, and any closer-than-comfortable margins will be attributed to the down-ballot Trump effect. It's a dynamic that may carry significant weight in November, even if McCain and Rubio cruise to their nominations as expected. Both men will face off with aggressive Democratic challengers in the fall. They will need the Trump base, whether they like those voters or not. On the other side of the aisle, the Bern gets a test in the primary challenge against Debbie Wasserman Schultz. Bernie Sanders made clear his distaste for the DNC chair, so much so that she was forced out of her job after her emails were hacked on the eve of the convention. Sanders helped raise money for her primary challenger, Tim Canova, in a Florida race that's drawn liberal interest in the wake of the convention. All three big-name incumbents are expected to move on, though not without some bruises.

4.

Fired Manager Corey Lewandowski Still Involved in Donald Trump Campaign

As Donald Trump arrived in Manchester, New Hampshire, for a rally a week ago, he stepped out of his motorcade and was greeted by a familiar face: Corey Lewandowski. Lewandowski had been fired in late-June after serving as Trump's first campaign manager, ABC's JOHN SANTUCCI notes. Now, a few weeks and a lucrative cable network contract later, Lewandowski is back in the fold, according to multiple campaign sources. They describe Lewandowski's relationship with the candidate as "stronger than ever." http://abcn.ws/2bRBHkF

5.

Clinton on Debates: 'I Don't Know Which Donald Trump Will Show Up'

Less than a month ahead of the first presidential debate at Hofstra University in New York, Hillary Clinton spoke candidly about her preparations, saying, "I am not taking anything, anyone or any place for granted." "I do not know which Donald Trump will show up," Hillary Clinton told donors at a private fundraiser in East Hampton, New York. Then, Clinton asked attendees for tips on how to face their fellow New Yorker. "I want any of your thoughts or ideas about how I should debate Donald Trump, just to name one thing. Seventy-one days left in the campaign," said the former secretary of state. The first of three debates is Sept. 26, and both campaigns are aware of how many people will be watching and how performances will influence the decisions of voters, writes ABC's JOSH HASKELL. http://abcn.ws/2bEpEGt

6.

Huma Abedin Announces Split From Anthony Weiner

Huma Abedin, a top aide to Hillary Clinton, announced Monday that she is separating from her husband, disgraced former Congressman Anthony Weiner. The announcement comes in the wake of the latest allegations of Weiner sending lewd messages to a woman online which were revealed by The New York Post last night. "After long and painful consideration and work on my marriage, I have made the decision to separate from my husband. Anthony and I remain devoted to doing what is best for our son, who is the light of our life. During this difficult time, I ask for respect for our privacy," Abedin said in a statement. ABC's MEGHAN KENEALLY has more: http://abcn.ws/2c3Xep8

7.

Hillary Clinton's Lead Cut in Half in New National Poll

Hillary Clinton's wide lead over Donald Trump in the race for the White House has been cut in half, according to a new national Monmouth University poll released Monday. The Democratic nominee held a wide 50 percent to 37 percent lead in the wake of her party's convention in a Monmouth poll in early August, but now that lead appears to have tightened to 7 percentage points -- 46 percent to 39 percent among likely voters. But Trump still faces a statistically significant deficit with just 70 days remaining until Election Day, reports ABC's RYAN STRUYK. http://abcn.ws/2bUQEn2

Best of the 2016 Primary Debates

Inside the Republican National Convention

Inside the Democratic National Convention

In Depth: The Latest ABC News-Washington Post Polls