Welcome to The Campaign Moment, your guide to the biggest developments in the (rapidly shrinking) 2024 campaign.

Now, that development is the demise of the DeSantis campaign. At one point, Ron DeSantis was the only candidate who seemed to seriously threaten Donald Trump’s stranglehold on the reins of the Republican Party; he even led Trump head-to-head in a bunch of polls. But that was a long time ago, and now he’s out.

The Florida governor ended his campaign Sunday. That means a GOP field that featured five major candidates less than two weeks ago is down to two. And the head-to-head race between Trump and Nikki Haley means the New Hampshire primary Tuesday could deliver a decisive verdict.

Perhaps most significantly, though, it could provide the clearest distillation to date of where the GOP stands in the battle between Trumpism and traditional Republicanism — and just how dominant the former is.

The end of DeSantis’s campaign has invited plenty of looking back. Few campaigns have featured such promise and so steadily petered out. DeSantis had virtually limitless resources, yet he proved to be an awkward candidate selling a vision that voters had little use for.

In some ways, it calls to mind another Florida governor who led in early primary polls and floundered in the face of Trump: Jeb Bush in 2016.

But the new battle lines in the 2024 nominating contest provide something that 2016 campaign never really did: a one-on-one matchup between Trump and traditional Republicanism.

The effort to defeat Trump in 2016 was marred in some ways by the failure to isolate a single alternative. Sen. Ted Cruz (R-Tex.) and former Ohio governor John Kasich both stuck around until early May, dropping out within a day of one another.

The idea that distilling that race to two candidates earlier might have changed the result was overblown. But nobody ever really got the chance to press a binary choice between Trumpism and a more traditional brand of conservatism.

We now have that — in spades — with Haley versus Trump. More than perhaps any candidate in either 2016 or 2024, the former South Carolina governor and U.N. ambassador exudes the 2000s-era Republican Party and Reaganism. She’s hawkish on foreign policy, relatively pragmatic, talks seriously about cutting spending (even Social Security), and isn’t so consumed with provocation and owning the libs.

It’s basically as if the 2016 campaign actually came down to Trump against a Bush.

The problem for Haley is that it seems clear what voters will choose. The party has drifted away from what were once standard conservative positions — on issues such as trade, foreign policy and entitlements — that practically defined it in the 2004 election. While Ronald Reagan had long been Republicans’ clear choice for greatest recent president, Trump is now nipping at his heels.

The reason Haley provides such an important test case is not just because she’s the first to get Trump one-on-one, but also because she has largely stuck to these old-style Republican positions in the process. She has kept on talking about raising the Social Security retirement age (for young workers). She has made passionate cases for standing by Ukraine, even as the GOP base has headed in the opposite direction. While DeSantis tried to marry a more traditional-seeming candidate with “America First”-style owning the libs, Haley has stuck to her vision.

Haley will in all likelihood come up well short. She is polling best in New Hampshire, and she still trails Trump there — including by double digits in the most recent Washington Post-Monmouth University poll. The most recent national poll testing a head-to-head race between her and Trump showed Trump leading by more than 50 points. Virtually all surveys suggest DeSantis supporters will break for Trump.

But the margins will be extremely instructive when it comes to just how much the modern Republican Party has shed its old skin.

There is little doubt that DeSantis timed his exit — after finishing second in Iowa — to avoid some potentially embarrassing losses that could hamstring his future aspirations. Despite his campaign’s failure, DeSantis remains in good standing with the Republican Party and even with Trump’s base, which he could build on if he runs in 2028.

But at least for now, it appears hard feelings remain. DeSantis “kissed the ring” in endorsing Trump on Sunday, but he didn’t exactly linger there.

DeSantis’s scripted four-minute video featured a mostly perfunctory endorsement of Trump. He didn’t really praise Trump, instead casting this as the result of Trump’s big lead in the polls, his pledge to support the party’s nominee, and how Trump is better than President Biden.

DeSantis also made rather conspicuous allusions to how Trump’s presidency was “stymied” by his opponents — the logical extension being that Trump couldn’t overcome them — and to his disagreements with Trump on the pandemic. DeSantis even saw fit, for some reason, to mention Trump’s “elevation of Anthony Fauci.”

(That last one was a late flash point in the campaign.)

The lack of enthusiasm hasn’t yet let to a large backlash, but former Trump adviser Stephen K. Bannon on Monday labeled DeSantis a “9-year-old petulant child.”

We wouldn’t expect DeSantis to emulate Cruz’s approach and pursue a vendetta against Trump after dropping out. The course of things in the GOP make clear that embracing Trump is necessary for any ambitious Republican’s future. Perhaps DeSantis worried what it would look like to effusively praise Trump just a week after deriding how transactional it is for Republicans to kiss Trump’s ring.

But this dynamic is certainly something worth watching.

The Iowa caucuses provided a reality check when it comes to just how much election denialism pervades the GOP; nearly two-thirds of caucus-goers said Biden’s 2020 win wasn’t legitimate.

And perhaps no bigger chasm looms over the New Hampshire primary, as a nugget from the new Post-Monmouth poll shows.

The poll shows fewer voters there subscribe to Trump’s false stolen election claim; 51 percent say Biden won due to voter fraud, while 42 percent say he won fair and square.

But look at how those voters break down: Trump supporters say 82 percent to 11 percent that Biden won because of fraud, while Haley supporters say 87 percent to 8 percent that Biden’s win was fair and square.

“Was the notion of a competitive Republican primary just a mirage?” (Washington Post)“Haley’s last, best hope for the Republican nomination” (Washington Post)“Trump recruits South Carolina leaders to undermine Haley ahead of N.H. primary” (Washington Post)“The Lost DeSantis Moment” (New York Times)“A patchwork anti-Trump crew is rallying around Nikki Haley” (Politico)