I love DeSantis. I think he's proven to be one of the very best governors ever and I would vote for him in a heartbeat, but Rich is 100% spot on.
We're eight years into major political realignment.
The coalitions (and demographics) that made GOP presidential candidates like George Bush 43, Bob Dole, George Bush 45, John McCain, Mitt Romney, and everyone other candidate since Reagan not named Trump "competitive" no longer exists.
At the presidential level any Republican that is still too closely associated (fairly or unfairly) with the GOP establishment, RINOs, foreign policy neoconservatives, pro-big business Wall Street/Chamber of Commerce types, or even just normal looking (1988 - present) mainstream conservativism cannot win in the Rust Belt (except Ohio, sometimes), any of the northern swing states, or Nevada... and would get slaughtered in the other northern states that swung heavily for Trump in 2024 (that he still lost).
Moving forward, any candidate that is not sincerely enough and sufficiently "Trumpy" (MAGA/America First) will get absolutely slaughtered in a national election (will be capped out at about a 268 maximum Electoral Vote potential).
Trump, on the other hand, has forged a larger, more diverse, and more nationwide MAGA/America First coalition for future Republican candidates to tap in to, but only if that future GOP presidential candidate can successfully convince the voters that he/she is as opposed to the toxic brand of post-Reagan "Republicanism" as Trump is. These voters, who have been lost to us since 1992 when Ross Perot courted them (or in the case of Hispanic voters have never been ours), have so far proven that they will come out to vote for Trump, but not, for the most part, other Republicans yet.
Over the next four years, therefore, our principle task as a party from a branding standpoint is to PROVE to the voters that we have sufficiently and finally broken away completely from the kind of Republicanism that still dominates in the US Senate.Getting back to DeSantis... the people who ran his presidential campaign, the donors who supported it, and their messaging severely damaged his image with these new Republican-leaning voters. Regardless of how he has governed (which has been awesomely IMO), DeSantis became (unfairly IMO) associated in their minds with mainstream/establishment Republicanism which they loathe.
Vance in '28