Trump and Clinton count on Tuesday's primaries to boost leads

LIVE COVERAGE: ​CBCNews.ca will be liveblogging Tuesday night's U.S. presidential primary results and will livestream all the candidates' speeches from the five state contests.

Donald Trump and Hillary Clinton are counting on voters in five states today to give them enough delegates to make it almost impossible for their rivals to catch up.

In what is dubbed the "Acela primary" because of the Amtrak train that runs along the U.S. northeast corridor, Republicans and Democrats will vote in Rhode Island, Connecticut, Pennsylvania, Delaware and Maryland.

A total of 172 Republican delegates are at stake for Trump, Texas Senator Ted Cruz and Ohio Gov. John Kasich. Clinton and Bernie Sanders are competing for 385 delegates. Big victories for Clinton and Trump will allow them to pad their delegate counts and break away from their competitors. If they don't meet expectations, it will prolong their respective nomination fights and prevent them from focusing on the general election this fall.

• Trump's party rivals briefly join forces to stop him
• Why black votes matter to Sanders in Maryland

The states are favourable territory for Trump and Clinton, who are heading into the contests in strong positions in polls. All of the candidates packed their final day of campaigning with multiple events in the five states, except for Cruz.

He is already looking ahead to Indiana and spent the day courting voters in that state, which holds its primary next week. It emerged late Sunday that he and Kasich have agreed to a pact whereby Cruz will concentrate on Indiana while Kasich puts his resources into Oregon and New Mexico.

Their deal is an attempt to deny Trump the 1,237 delegates he needs to win the nomination in advance of the party's convention.

Trump blasted the Cruz-Kasich partnership as a desperate move. Kasich shrugged that off while campaigning in Philadelphia on Monday and said it just makes sense to use resources effectively.

"What's the big deal?" he asked reporters as he shovelled eggs into his mouth at a diner.

Wild card delegates could be key

Cruz said it's Trump who's desperate. "It is abundantly clear that nobody is getting 1,237. We are heading to a contested convention."

Tuesday's jackpot of delegates for Republicans is in Pennsylvania, where 71 are at stake, but there's a twist in that primary that could prove crucial for Trump if the race results in a contested convention.

• Trump nomination could hinge on wild card delegates

Trump has a double-digit lead in the polls, and if he wins the statewide vote, he is guaranteed 17 delegates.

But the rest of them, 54, are unbound delegates and can vote for whoever they want at the convention. If he doesn't nab the nomination in advance, the unbound delegates could push Trump past the threshold to win on the first ballot, or not.

Kasich's chances in the state are helped by the fact that he grew up there, in a small town called McKees Rocks, and that he's the governor of a neighbouring state. Pennsylvania also has more moderate Republicans than other states, and that works in Kasich's favour in certain parts of the state.

Jeff Brauer, a political science professor at Keystone College in La Plume, Pa., said Trump is finding his support in southwestern Pennsylvania, where the once strong steel and manufacturing industries have been decimated.

His promises to bring back jobs and fix trade deals that he blames for unemployment are resonating. "Pennsylvania is a good state for Donald Trump because there is a large population of disaffected voters, especially economically," Brauer said. "They feel like they have been left behind in the economy and they feel like Donald Trump is speaking to them and for them."

On the Democratic side, Clinton and Sanders are fighting for 210 delegates in Pennsylvania, which will be assigned proportionally. Clinton had a double-digit lead over Sanders in the latest poll.

Bad timing for Sanders with youth vote

"This is basically a Clinton state," said Terry Madonna, director of the Center for Politics and Public Affairs at Franklin and Marshall College in Lancaster, Pa. "She has deep roots here."

Clinton's father was from Scranton, she grew up visiting the area and she and her husband, former president Bill Clinton, cultivated longstanding relationships there. Their daughter is also married to the son of a former Pennsylvania congresswoman.

A local pizzeria near Scranton is such a huge supporter of Clinton it invented a special "Madam President" pizza in her honour. It's in the shape of Clinton's campaign logo and features hot sauce, her favourite condiment.

Sanders has an uphill battle there and winning Pennsylvania would be "a stunning upset" on his part, Madonna said.

Sanders is enormously popular with younger voters and Pennsylvania has a high student population that would normally work in Sanders's favour. Unfortunately for him, the primary comes as classes are wrapping up, assignments are due and exams are looming.

The Vermont senator always says that when turnout is high, he does better, and in these primaries it could hurt him if students stay home.

Sanders looks to narrow gap

Another challenge for him in the states voting Tuesday is that four out of five of them are closed primaries, meaning only registered Democrats, not independents, can vote. Sanders has done better in states where he's been able to draw on support from independents.

Maryland has the second-most delegates at stake, and there, too, Clinton has a solid lead. Polling indicates they are in tighter races in Rhode Island and Connecticut.

Ben Jealous, an aide on the Sanders Maryland campaign, said in an interview that Clinton's popularity is due in part to the state's proximity to Washington, D.C.

"We've always known Maryland would be a big challenge," Jealous said. "Our job in Maryland is to narrow the gap as much as possible."

If Clinton does as well as expected Tuesday, it will make it even harder for Sanders to catch up in the delegate count ahead of the party's convention in July. His campaign insists he's not dropping out before then and his supporters are encouraging him to stay in the race.

At a rally in Baltimore over the weekend, one of them waved a sign: "Keep Going Bernie. Don't Stop."