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The race for the White House has moved to the northeast with five states – Pennsylvania, Maryland, Connecticut, Rhode Island and Delaware – served by the so-called “high-speed” Acela train voting on Tuesday. In the Republican race, Donald Trump is hoping to build on the momentum from his big win in New York last week as he tries to reach the 1,237 delegates needed to avoid a contested convention.

To help understand the convoluted battle for delegates, we have compiled an explainer on contested conventions. If you’re confused, believe me you belong to a big club, including Trump who has been slower than Ted Cruz in learning the ropes. Trump recently brought in Paul Manafort, a veteran Republican operative, to help him win the shadow battle for delegates, but there are signs that the billionaire is unhappy with Manafort’s efforts to make him sound and appear more presidential.

In the Democratic race, Hillary Clinton has an almost unassailable lead over Bernie Sanders. Clinton would love nothing more than for Sanders to quit so that she can focus on attacking the Republicans. But the Vermont senator has raised so much money that he can afford to stay in the race through the Democratic convention in Philadelphia in July. That would allow him to pressure Clinton into adopting some of his message to ensure his fans vote for her in November. Trump has flirted with an independent run in the past, but today he was urging Sanders to do the same thing – which of course would help his chances if he and Clinton are the contenders in the general election.

“Bernie Sanders has been treated terribly by the Democrats—both with delegates & otherwise. He should show them, and run as an Independent!” Trump tweeted earlier today.

According to the polls, Trump has a clear lead in Tuesday’s primaries. There are 172 Republican delegates at stake in the five states. Pennsylvania is the most important given its 71 delegate haul, but the bulk of those are free to vote for any candidate at the convention, meaning that even a big victory for Trump may not necessarily help his convention chances. Cruz and John Kasich, the Ohio governor, are desperately trying to prevent Trump from reaching 1,237, which at this point is both candidates’ only realistic chance of winning the nomination.

Polls close at 8pm and you can find our coverage here. Follow us on Twitter at @DimiSevastopulo and @Courtney_FT and on Instagram.

Thanks for reading. Demetri Sevastopulo, Washington Bureau Chief.

Click here for full FT coverage of the 2016 race.

On the trail

Sanders to reassess race after tonight’s vote But the Vermont senator has no plans to drop out. (NYT)

Yet another senator declines to endorse Cruz The Texas senator’s senior home-state colleague, John Cornyn, again declined to offer his support, instead criticising Cruz: “Clearly, he didn’t come here to remain in the Senate. He came here to run for president.” (TPM)

The man who beat Trump In the early 1990s securities analyst Marvin Roffman gave a negative quote about the prospects of the Republican frontrunner’s upcoming Taj hotel project, criticising its shaky financing. Trump went to war on him, getting Roffman fired and smearing his name in the media. Roffman sued. Trump settled for a princely sum. Now, Roffman plans to vote for him. (Politico)

Chart of the day

Today is Clinton’s chance to end the Democratic race. (fivethirtyeight)

Number of the day

61%25% Clinton’s share of the vote v Trump’s share, among millennials, according to a new Harvard poll. (HIOP)

Soundbites

“Bernie Sanders has been treated terribly by the Democrats—both with delegates & otherwise. He should show them, and run as an Independent!” – Trump, offering advice on Twitter. (Twitter)

Campaign commentary

Before ‘unity’, Sanders must stay in the fight (Katrina vanden Heuvel, WaPo)

It’s okay to end friendships over Trump (Isaac Chotiner, Slate)

Pennsylvania, where everyone is furious (Emma Roller, NYT)

Political sideshow

Trump v Lena Dunham The former reality TV star said he had to win in order to ensure that the Girls creator makes good on her pledge to move to Canada. (NY Post)

Today’s RCP poll average

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