And I do mean “mega”: More than 30,000 people are expected. The answer’s obvious if you know the primary schedule this year, but if you don’t, this must seem like a headscratcher. Why waste even a day in Alabama when you could be spending it in the more important early primary states like Iowa, New Hampshire, or South Carolina?

Check your calendar, writes Joshua Green.

Here is the Trump political logic: “Alabama is extremely critical,” a close associate of Trump’s told me (actually, we agreed I’d call him “a close associate of Mr. Trump”). “You have Iowa’s caucus on February 1st, New Hampshire on the 9th, and South Carolina on the 27th.” The race, this associate explained, would not be wrapped up by then. According to this political calculus, the crucial moment arrives three days later, on March 1st, with the “SEC primary”—the belt of Southern states that encompass the Southeastern Athletic Conference—when Alabama, Texas, Georgia, Arkansas and several others hold their primaries.

Trump is currently leading the polls in many of these states. A new Texas poll has him in first place, beating actual Texans Ted Cruz and Rick Perry. He’s dominating the field in Alabama, as well, doubling the support of second-place finisher Jeb Bush, from neighboring Florida. (Trump is winning in Florida, too, according to a new Quinnipiac University poll, which, although it is an SEC state, doesn’t hold its primary until March 15th). If Trump sweeps the early states, or even just wins Iowa and South Carolina, these advisers believe he could effectively lock down the Republican nomination by sweeping the SEC primary on March 1st. “He feels he wins the nomination on 1 March w/ a sweep of the populist anti-establishment South,” another adviser emailed. “That’s when Trump’s ‘nationalism’ coupled with Sessions’ ‘populism’ comes to full fruition.”

It’s not an “Alabama rally,” it’s a “southern rally.” Alabama’s being chosen, writes Green, because it’s Jeff Sessions’s home state, another way for Trump to signal his commitment to border-hawkishness. Usually it’s Florida that enjoys the prestige of being fourth out of the four key early-state primaries, but with the SEC states set to vote two weeks earlier (and with Florida expected to be a battle between Bush and Rubio), the south may set the eventual nominee on his path to victory next year more so than Florida will. The social conservatives in the race have been eyeing March 1st as their breakout for months. Huckabee’s been talking about it since before he announced; Ted Cruz is convinced that that’s when he’ll emerge from the pack on the right; Scott Walker’s been campaigning down south too, trusting that his own evangelical cred will make him a contender there even though he’s a Wisconsinite. The southern primaries will be even more important as a winnowing device if Iowa, New Hampshire, and South Carolina split two or three different ways. Imagine if Walker, Trump, and Cruz each win one of those; the SEC will effectively decide who the “real” frontrunner is.

The danger here for establishmentarians is that there are so many social-con candidates hoping to make a splash on March 1st that they could carve up the right-wing vote among them, leaving the leading moderate with a clear path to victory. A few months ago, with Jeb Bush best positioned to be that moderate, that seemed like a sweet deal for the donor class. Now, with Trump having leaped past Jeb, it’s a disaster in the making for them. And Trump, of course, isn’t a niche moderate the way Bush is; he can pull votes on the right too thanks to his nationalist pitch, which makes him a threat to win. This is what I meant a few days ago when I said that it’s silly to think the establishment will sit around anxiously watching Trump build support while they let Bush, Walker, Rubio, etc, divide the “Not Trump” vote. If Trump is still a player in the race circa October or November, they’re going to unload on him with ads and you’ll start seeing some major donors gravitate towards whichever center-right candidate looks most capable of going the distance in an all-out “Stop Trump” effort. They can’t, and won’t, risk Trump winning Iowa and New Hampshire while Ted Cruz wins South Carolina, leaving their two least favorite candidates battling it out for supremacy in the SEC primary. They need someone from the center to contend early and do well enough that he can weather the storm of a big day for Trump or Cruz on March 1st. Which makes me wonder, in all seriousness, how long they’ll be willing to stick with Bush if he’s still limping along with 15 percent nationally in November. Do you want to bet the “Stop Trump” initiative on an uncharismatic dynast? You’re better off rolling the dice with Rubio, no?

Two more points on this. One: Ted Cruz will continue his entente with Trump for as long as he can, possibly even through Iowa if he fears Trump voters would write him off for attacking their guy, but he obviously can’t afford to lose South Carolina and the SEC primary. He’ll have no choice but to start picking Trump apart as a fake conservative before March 1st. Two: Thanks to the size of the field and the rise of Super PACs, it’s possible (although not likely) that multiple candidates will have the votes and money to run all the way to the convention. Every state counts and there are a lot of states in play in the SEC primary. Being on top of the pack with electoral momentum on March 1st could mean an early delegate bonanza that leaves the new frontrunner hard to catch. Whoever emerges might well end up with the most delegates at the convention, even without a clear majority, and since he’d be the choice of the region that represents the party’s base, he’d have an extra claim for why he should be the nominee. It makes all the sense in the world for Trump to start competing in the south now.

Exit question per today’s 500-point Dow dive: If we end up with a stock-market crash driven by China, that should pretty much lock things up for President Trump, no?