If Donald Trump wins New Hampshire, here's what happens next

It appears the blustery businessman will actually triumph in a storied electoral contest. What happens then?

Donald Trump is likely to win the New Hampshire primary. Let’s stop a second to let that sink in.

A year ago that seemed an impossible accomplishment. Six months ago it looked highly improbable. Now it’s maybe inevitable – Mr. Trump has a 17-point lead in the final RealClearPolitics rolling average of New Hampshire state polls.

Yes, you never know until actual voting starts, and in early primary states lots of voters make up their minds at the last minute. Tomorrow we might be opining about how surprise winner John Kasich shocked the world.

But right now it appears the blustery businessman will actually triumph in a storied electoral contest. If he does, congratulations to him. What happens next?

Given how wrong we’ve been about Trump in the past we’re leery of making a hard prediction. However, there are warning signs in New Hampshire and other early voting states that indicate the Trump phenomenon may have peaked and he’s vulnerable to a rival or rivals who can consolidate anti-Trump sentiment.

The first is that he seems to have hit his voter ceiling. He’s pulling in about 30 percent of the New Hampshire GOP electorate, according to polls, and he needs to do better than that down the line if he’s going to win.

Why? Because winnowing works. Two or three candidates are likely to drop out following the Granite State vote. More will follow after the Republican South Carolina primary on Feb. 20. By the end of March, it’s quite likely that the GOP race will be down to Trump, Ted Cruz, and one (or two) party establishment favorites to be named later.

If Trump’s ceiling is 30 percent, he can’t win in a two, or even three-person race. And in the RealClearPolitics rolling average of major surveys he’s now dropped to 29.5 percent.

Second, Trump’s firewall, the South, is beginning to look less Trumpian. Though it has many lower-income, less-educated voters, a group disproportionately drawn to the real estate magnate, the most recent polls show him slipping in key Southern states.

He still leads in Georgia, Florida, and North Carolina, but his numbers are down in all three and below 30 percent in all cases, notes data journalist site FiveThirtyEight. He’s tied for second in Arkansas, behind Ted Cruz.

“Any one of these surveys in isolation wouldn’t be a big deal for Trump … But the fact that he’s under 30 percent in four Southern states suggests that he’s vulnerable in the region,” writes FiveThirtyEight’s poll expert Harry Enten.

Third, Trump’s been exposed as a loser, as well as (maybe) a winner. His surprisingly poor showing in the Iowa caucuses punctured the myth of a Trump steamroller winning all the way to the Cleveland national convention.

All this doesn’t mean Trump is doomed. We’ve learned our lesson about predicting his inevitable Icarus-like fall.

What it does mean is that Trump’s way forward is unclear. And when the end comes for a candidate in a primary race, it comes quickly. A surprise New Hampshire defeat, for instance, would be a Trump disaster.

“Losing a presidential primary is often like going bankrupt. It happens slowly, then all at once,” wrote Vox founder Ezra Klein last month in a piece outlining how Donald Trump might lose.