Paul Singer

USA TODAY

Election Day starts early and runs late. Here are 7 1/2 things to keep in mind as the long parade plays out.

1. Early results may matter

The five most critical swing states this year are all in the Eastern time zone: New Hampshire, Pennsylvania, Florida, North Carolina and Ohio. Donald Trump needs to win at least one and possibly two of these to have a shot at the White House; by 11 p.m. Eastern, we may have enough results to tell us whether he's still in the game.

2. Late results may matter

Assuming Trump has made it through the early vote gauntlet, Nevada, Arizona and Utah are the other fascinating battlegrounds. Utah is a wild card, because while it almost always votes Republican, this time around independent Evan McMullin could pull enough votes to take the state away from Trump.

3. Michigan? Really?

Donald Trump has made a major pitch for Michigan the past few days, a state that Hillary Clinton has led in the polls by a comfortable margin for most of the election season. The polls began to tighten here after FBI Director James Comey's Oct. 28 announcement that the bureau was looking at a new batch of emails. If Trump can turn this traditionally blue state red, that would be yuuuuge.

4. Remember the U.S. Senate

A few weeks ago when it appeared that Trump might lose big to Clinton, some Republican-leaning groups began airing ads saying basically "Clinton is going to win so vote for your Republican senator to maintain a 'check and balance' against her." Democrats are very likely to capture a Republican Senate seat in Illinois and reasonably likely to capture another one in Wisconsin. The math gets messy, but watch Pennsylvania, North Carolina, New Hampshire and Nevada. Democratic wins there will almost certainly give them the Senate.

5. Forget the U.S. House

There was never a realistic expectation that Democrats would win control of the House, given that they would need to flip 30 seats to overthrow the Republican majority. Best guess has veered between five and 15 Democratic "pickups" on Tuesday; more than that would be the equivalent of a political earthquake. There are still some interesting races to watch, like Martha Roby in Alabama, a Republican who is being challenged by a pro-Trump write-in candidate, and Darrell Issa of California, the former head of investigations for House Republicans who is now in jeopardy of losing his seat. But the big picture seems unlikely to change much.

6. CAUTION: Exit polling ahead

Media like USA TODAY and other will have a batch of exit polls—very useful for gathering information about who voted, what motivated them to votes, etc. Unfortunately, the first reports about exit polling are likely to be public shortly after 5 p.m. Eastern, but these should be treated with Serious Caution. Early exit polls are notoriously unreliable. Do NOT be fooled into believing we know the outcome based on early exit polls.

7. 2020 starts tomorrow

Yes, we have all been desperately begging for this election to be over, but sadly, the 2020 election campaign begins Wednesday. Once we know who won the White House, we can immediately begin to speculate on who will be running against the incumbent in four years. If Trump wins, watch for instant speculation about Democratic senators like Amy Klobuchar of Minnesota or Cory Booker of New Jersey or a second run by former Maryland governor Martin O'Malley. If Clinton wins, expect somebody to instantly resurrect the hypothetical campaigns of Scott Walker, Ted Cruz and Marco Rubio (if he won his Senate race).

7 1/2: Need a ride to the polls?

Ride share companies Uber and Lyft both have apps for that.

More election coverage from USA TODAY:

• How to make sense of what's happening as polls close

• Plot Trump's or Clinton's path to 270 electoral votes

• See the latest national and state presidential polling averages

• Check out poll closing times in each state

• Candidate info and ratings for all races