1. The timeline
The first results will be available when polls close at 12.30pm NZT in North Carolina and Ohio. North Carolina has lots of early absentee voters, so close to half the ballots could be counted and reported in the first half-hour. Ohio also is a big absentee-vote state, so expect a fast, early count there as well. At 1pm, final polls close in Florida, Illinois and Missouri. Since most polls in Florida close at noon, there will be a lot of votes ready to report right at 1pm, allowing for possible early calls on both sides. Illinois and Missouri are slower counting states. First thing in the morning, the Northern Mariana Islands, where 471 people voted, chipped in all nine of its Republican delegates for Donald Trump.
2. And then there were …
Will it still be a four-man Republican race this afternoon? Senator Marco Rubio has been staking his candidacy on a winner-take-all victory in his home state of Florida but hasn’t specified what a loss would mean. Ohio Governor John Kasich has acknowledged that a winner-take-all triumph in Ohio is essential for him, but in recent weeks he’s stopped short of explicitly saying he would drop out should he lose.
If they can’t win at home, do these two candidates quickly exit stage left, sleep on it before bowing out – or dig up some shred of a rationale to slog on?
3. Duelling Trumps
Which Trump will turn up for his ritual “press conference” after the votes roll in? There’s the Trump who is positioning himself for the general election and trying to act more presidential. And there’s the scrappier Trump, still trying to elbow his rivals out of the race. Scrappy Trump could also decide to train his focus on Democratic front-runner Hillary Clinton if she has a good day.
4. Clinton’s aim
Clinton held off on a full pivot toward the general election after Senator Bernie Sanders snatched Michigan from her last week. Today’s results should give her a lot more information – and delegates -to decide when it’s safe to look past Sanders and train her focus on November. Her speech will tell a lot about her thinking on that.
5. Cruz’s aim
Senator Ted Cruz, too, will have to decide where to focus his attention. Watch to see if he spends more time trying to nudge Rubio and Kasich out of the picture, or takes it to straight to Trump.
6. What the polls say
Yesterday’s opinion polls on RealClearPolitics.com showed Trump leading by 17-25 points in Florida and 11 points in North Carolina. Kasich was ahead by five to six points in Ohio. Clinton leads by 21-26 points in Florida, five to 14 points in Ohio, 19 points in North Carolina and three points in Illinois. Sanders was ahead by one point in Missouri.
7. The midpoint
Check the Republican delegate count at the end of the night. A five-state sweep would allow Trump to cross an important threshold – stacking up more than 50 per cent of the delegates awarded so far. After his win in the Northern Mariana Islands earlier today, Trump went into the voting with 469 delegates to 370 for Cruz, 163 for Rubio and 63 for Kasich. It takes 1237 delegates to win the GOP nomination.
8. Clinton’s cache
With Democrats continuing to dole out delegates on a proportional basis, see where Clinton’s delegate stash stands at the end of the night. She went into the contests with 768 pledged delegates compared to 554 for Sanders, according to a count by AP. Including superdelegates, Clinton holds 1235 total delegates, more than half the amount needed to clinch the nomination, while Sanders has 580.
9. Race, age
Dig into the exit polls to check on whether Sanders can continue to make Rust Belt inroads with black voters, a huge source of support for Clinton. In his surprise Michigan win last week, Sanders got nearly 3 in 10 black Democratic voters. In earlier states, mainly in the South, he was getting only about half that level of support. Also, check whether younger voters turn out in force for Sanders. In Michigan, 45 per cent of Democratic voters were under 45, the most of any state so far, and two-thirds of them supported Sanders.
10. Late deciders
The exit polls also can give clues about whether late deciders on the Republican side are continuing to break against Trump – and whether there are enough of them to make a difference. So far, about a third of voters have been making up their minds in the last week, and they’ve been splintering among Trump alternatives. A spike in late-deciders moving against Trump could signal concern about the increasingly tense tone between Trump and his supporters, and the protesters at his rallies.