Paul Singer

USA TODAY

Tuesday's presidential primaries in five states may be consequential, but they are not likely to be late. All five Amtrak corridor states — Pennsylvania, Maryland, Connecticut, Delaware and Rhode Island — close their polls at 8 p.m. ET, and polling suggests that winners may be declared pretty early in many of the races. Here's how to watch results of the Amtrak primaries:

Pennsylvania's White Elephant primary

The most intriguing race Tuesday may be the one that will not be decided Tuesday: the race for Pennsylvania's 54 "uncommitted" Republican delegates, who will be selected Tuesday without declaring whom they plan to support at the convention. Pennsylvania's 17 statewide Republican delegates are winner-take-all and are most likely to go to Donald Trump, who has been leading the polls there by an average of 20 points. The rest will be a surprise package to be unwrapped in Cleveland and could be critically important if Trump falls narrowly short of the 1,237 delegates he needs to win the nomination on the convention's first ballot.

On the Democratic side, Hillary Clinton leads in the polls by a narrower margin; like all Democratic primaries, the 189 delegates here are distributed proportionately, so both she and Bernie Sanders will come away with delegates. The problem for Sanders is that she already leads him by nearly 300 delegates won in prior contests and she also has been endorsed by more than 500 superdelegates, while he has fewer than 50 of these party leaders backing him. With 384 pledged delegates at stake in the voting Tuesday, Clinton cannot seal the nomination, but she can put herself within sight of the finish line.

Small pie slice in Delaware

The First State shall be last in total delegates awarded Tuesday — 16 for Republicans, 21 for Democrats — but it is a winner-take-all state for the GOP, so somebody will get a nice prize here while the others get nothing. It is also worth noting that in 2008, Connecticut voted on Super Tuesday while the GOP race was still competitive, and 50,000 GOP voters cast a primary ballot. If the same number shows up, it would mean approximately 25,000 (or fewer) votes would be enough to deliver 16 delegates. As we have mentioned before, in Ohio, Trump got more than 700,000 votes and collected zero delegates.

There is no meaningful polling in Delaware, but Trump is believed to have the edge here.

On the Democratic side, users of the political prediction market Predictit are betting heavily on a Clinton victory in Delaware, for whatever that's worth.

Margins matter in Connecticut

The Nutmeg State is one of the Republican contests where the margin of victory matters. If a candidate tops 50% of the vote statewide, that candidate pockets all 13 of the statewide delegates. The 15 remaining delegates are distributed by congressional district, and in those five races, the biggest vote-getter in each district collects three delegates. Polls again show Trump with a big lead in Connecticut, and he has hit the 50% threshold in several recent polls.

Margins matter in the Democratic race as always because of proportional delegate distribution. There are 55 delegates at stake here and while Clinton has shown a lead in the polls, it is narrow enough to suggest this we might have to wait awhile before this race is called.

Little mystery in Maryland

Vote-counters in Terrapin country might turn in early — polls indicate that both Clinton and Trump will win by sizable margins. Of course, it is worth watching anyway because polls are sometimes wrong.

The state is winner-take-all for Republicans in nine separate races: 14 delegates are awarded statewide and three each in eight congressional districts.

Even if the presidential races turn out not to be close, keep your eyes on the Democratic Senate primary here. Seven-term congressman Chris Van Hollen and four-term congresswoman Donna Edwards are battling for the Democratic nomination to replace legendary Democratic Sen. Barbara Mikulski, who is retiring after 30 years in the Senate.

Rhode Island feeling the Bern?

The Biggest Little State in the Union could be Bernie Sanders' best chance for a win on Tuesday. A Sunday poll from Brown University showed Clinton leading Sanders 43%-34%, but it showed 16% undecided; Public Policy Polling released a survey Monday showing Sanders up 49%-45%. Clinton and Sanders were both in the state over the weekend, suggesting both campaigns see a tight race there. It would have been inconceivable this time last year that we would be staying up late to watch the Rhode Island Democratic primary results roll in, but it has been a Very Strange Year in politics, so we'll just add this to the oddities.

Rhode Island delegates in the Biggest Little State are divided proportionately on both the Democratic and Republican side, and the stakes are small on both sides, with 24 Democratic and 19 Republican delegates available, so the results won't significantly affect either race.

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Elections 2016 | USA TODAY Network