Now that Hillary Clinton beat Bernie Sanders in Nevada by five points, suddenly Super Tuesday is coming in just eight days, and the biggest single day of the primary season could wind up as essentially a tie between Hillary Clinton and Bernie Sanders, pushing the race on toward the convention without much change from where things stand now. Or it could allow Clinton to surge ahead in delegates, widening a lead that few people realize she already enjoys (more on that in a moment).

If that latter scenario comes after what looks like it will be a Clinton win in South Carolina on Saturday, it could send the race into its final stage.

That wasn’t exactly the idea behind putting a whole bunch of primary contests at this point in the campaign, but that’s what it has become. Super Tuesday came about because Southern Democrats wanted to increase their influence over their party’s nominating contest, and Republicans in the South soon agreed that it was a fine idea. They couldn’t move ahead of Iowa and New Hampshire (those states have laws mandating that they’re the first caucus and primary), so they decided to seek power in numbers. If a bunch of states from the South voted together, they realized, candidates would have to campaign heavily there and pay close attention (i.e. pander) to Southern interests. The first real Super Tuesday was in 1988, and since then, more states outside the South have joined in.

This year, 11 states will be voting on Super Tuesday, plus American Samoa and Democrats living abroad. All told, there will be 974 delegates at stake in the Democratic contest, or 40 percent of the 2,383 a candidate needs to secure the nomination. The big prize is Texas, with 252 delegates, followed by Georgia and Massachusetts with 116 each and Virginia with 110.

But that doesn’t mean the winner will simply wipe out the loser, because Democrats allot their delegates proportionally (on the Republican side, some states use a proportional system and others are winner-take-all). That’s why Clinton and Sanders are tied in the delegates they won in Iowa, New Hampshire and Nevada: each won 51.

But in the actual delegate score, Clinton enjoys a huge lead of 502-70. That’s because the Democratic system includes a thumb on the scale for that dreaded “establishment”: 712 superdelegates, mostly elected officials and party leaders, who can give their support to anyone they want. Clinton has that sizeable lead because so many of those superdelegates have already pledged to vote for her at the convention.

There hasn’t been a great deal of polling in the Super Tuesday states, so we don’t have a complete picture of what might happen. And of course, things could change over the next week. But we can get a hint from a series of polls recently released by Public Policy Polling, which included primary voters in nine of these 11 states (Colorado and Minnesota were the exceptions). In seven of the nine — Alabama, Arkansas, Georgia, Oklahoma, Tennessee, Texas, and Virginia — Clinton was ahead, by margins ranging from tiny (2 percent in Oklahoma) to overwhelming (34 percent in Georgia). Sanders led only in Massachusetts and his home state of Vermont. Many of these states are also heavy with the African-American voters with whom Clinton does particularly well.

That doesn’t mean Clinton is going to blow Sanders away next Tuesday. But the nature of the event, with so many contests spread over such a wide area, favors candidates with organization, resources, and the backing of local leaders and officials who can mobilize voters on their behalf. You can’t win Super Tuesday by going from coffee shop to VFW hall and meeting voters one by one — there just isn’t enough time.

It’s also important to remember that each contest is going to be affected by what happens just before it, as momentum shifts and voters’ understanding of the campaign changes. Sanders may be particularly vulnerable to the effects of momentum, because his campaign depends on voters maintaining their belief that he’s viable, and that confidence could be undercut dramatically if Clinton wins big in South Carolina, and the media storyline continues to be that she’s crushing him among African American voters, who will be crucial in the Super Tuesday contests.

Here’s another twist, relating to the contests that occur right after Super Tuesday: Bernie could be significantly hampered by spring break. As Darren Samuelsohn reports:

In all, more than a half million college students from 14 states will be on spring break at the same time that the presidential campaign train chugs onto their campuses, according to a POLITICO analysis of the March 5 to March 26 primary and caucus states.

The most important characteristic of this phase of the campaign is its speed. Unlike what has happened to this point, in March the contests are going to come in bunches, with barely time for a breath between primaries. That’s an environment where small leads can turn into big ones before you know it. The Democratic race is still close, but this is a dangerous moment for Bernie Sanders.