Can DeSantis Reset? What to Watch for in the 2nd G.O.P. Debate.

The Trump factor

Mr. Trump, who is under four criminal indictments, skipped the first debate and emerged much as he entered: the overwhelmingly dominant figure in the primary race. His opponents mostly jostled for position among themselves, declining to take significant swings at the front-runner in absentia. In the post-debate polling, Mr. Trump gained more support than any of the candidates who did appear on the stage.

Since then, as his legal cases play out in the courts, Mr. Trump has grown more extreme, and violent, in his rhetoric. He has suggested Gen. Mark Milley, the former chairman of the Joint Chiefs of Staff, should be executed for treason, accused “liberal Jews” of voting to “destroy” America and Israel, and seemed to threaten the judges and prosecutors in the felony cases against him.

So far, his rivals have not used those attacks to go after the front-runner as extreme, but with the first ballots to be cast in Iowa in January, time is running out. The Wednesday debate could be among the lower-polling candidates’ last chances to take aim before a large audience, as the Republican National Committee’s criteria to make the next debate stage is expected to become even more strict. It remains to be seen whether the second debate will persuade top donors still on the sidelines to consolidate behind an alternative to Mr. Trump.

Rather than attending the debate, Mr. Trump will appear with union workers in Detroit.

How Scott and Haley perform

Mr. Ramaswamy might have grabbed headlines with a pugnacious performance last go-round, but Ms. Haley had arguably the best night. She distinguished herself with her answers on abortion and foreign policy while seizing the opportunity to position herself as the “adult in the room” as her male rivals bickered. She raised more than $1 million over the 72 hours that followed the event, winning over Republican donors who have been looking for a plausible alternative to Mr. Trump. And she elevated herself over Senator Tim Scott, a fellow South Carolinian, as the next-generation conservative who could potentially appeal to independents and some disaffected Democrats.

Mr. Scott faded on the stage in Milwaukee. But while it’s critical for him to make a splash at the Reagan Library in order to eat into Ms. Haley’s gains, any spotlight-grabbing moments cannot tarnish his persona as the “happy warrior” with the winning smile and the hopeful message. A bad night, or just an invisible night, for Mr. Scott would dim hopes of a resurgence.