If the polls are right, there will be very little drama tonight in presidential races: Trump has massive leads over Haley in virtually every state. For instance, here's what our primary polling averages say in the six states with enough polling to calculate one:

Trump also leads by at least 42 percentage points in the few state-level polls we have this year from Alabama, Maine, Minnesota and Oklahoma. His lead is smaller, though still substantial, in the most recent surveys of Utah (27 points) and Vermont (30 points). Unfortunately, we're flying blind in the last three states; we don't have any polls of Arkansas since last fall, or any polls of Alaska or Colorado, period.

But what if … the polls are wrong? Even in the states where we've calculated averages, there is precious little truly recent polling. The only polls of Super Tuesday states conducted entirely within the last month were four of California, two of Maine, one of Minnesota, two of North Carolina, one of Texas, one of Vermont and one of Virginia. That's not a lot of data to go off.

Plus, primary polls so far this year have overestimated Trump's margin over Haley. This isn't necessarily unusual; since 2000, presidential primary polls have had an average error of 9 points. But the fact that the direction of that error has been consistent so far is … interesting. We usually caution against trying to predict the direction of polling error in advance, but this could — could — indicate that pollsters' likely-voter models for the primary are too weighted toward the Trump wing of the GOP.

As Geoffrey and I wrote yesterday, there are certain states — Colorado, Massachusetts, Vermont and Virginia — that seem demographically favorable for Haley. Despite what the polls say, I wouldn't be totally shocked if Haley pulled off a win in one of them. As noted, Colorado hasn't seen any polling this cycle, and Massachusetts hasn't seen any in a month. And while a poll gave Trump a 30-point lead in Vermont a few weeks back, the most recent poll of Virginia put Trump's lead over Haley at just 8 points among likely voters.

—Nathaniel Rakich, 538

It’s the biggest day of the primary season, and former President Donald Trump could very well sweep all 15 GOP presidential nominating contests today. With limited polling in many of these states, it’s not out of the question that former U.N. Ambassador Nikki Haley could pick off a state or two, but barring a massive shocker, the main question tonight is whether she’ll drop out and make Trump the presumptive Republican nominee.

Outside of the presidential race, it’s a day us election nerds have been waiting for — the first day of downballot primary season! We’ve got our eye on dozens of primary contests happening in Alabama, Arkansas, California, North Carolina and Texas, where November’s battle lines will be drawn as we find out which candidates will be on the ballot for everything from congressional seats to city councils.

As always, 538 analysts will be here bringing you the latest results and analysis as polls close, from Vermont and Virginia (7 p.m. Eastern) through Alaska (midnight). Thanks for joining us!

—Tia Yang, 538