For months, former President Donald J. Trump has been grumbling quietly to friends and visitors to his Palm Beach mansion about a rival Republican power center in another Florida mansion, some 400 miles to the north.
Gov. Ron DeSantis, a man Mr. Trump believes he put on the map, has been acting far less like an acolyte and more like a future competitor, Mr. Trump complains. With his stock rising fast in the party, the governor has conspicuously refrained from saying he would stand aside if Mr. Trump runs for the Republican nomination for president in 2024.
“The magic words,” Trump has said to several associates and advisers.
That long-stewing resentment burst into public view recently in a dispute over a seemingly unrelated topic: Covid policies. After Mr. DeSantis refused to reveal his full Covid vaccination history, the former president publicly acknowledged he had received a booster. Last week, he seemed to swipe at Mr. DeSantis by blasting as “gutless” politicians who dodge the question out of fear of blowback from vaccine skeptics.
Mr. DeSantis shot back on Friday, criticizing Mr. Trump’s early handling of the pandemic and saying he regretted not being more vocal in his complaints.
The back and forth exposed how far Republicans have shifted to the right on coronavirus politics. The doubts Mr. Trump amplified about public health expertise have only spiraled since he left office. Now his defense of the vaccines — even if often subdued and almost always with the caveat in the same breath that he opposes mandates — has put him uncharacteristically out of step with the hard-line elements of his party’s base and provided an opening for a rival.
But that it was Mr. DeSantis — a once-loyal member of the Trump court — wielding the knife made the tension about much more.
At its core, the dispute amounts to a stand-in for the broader challenge confronting Republicans at the outset of midterm elections. They are led by a defeated former president who demands total fealty, brooks no criticism and is determined to sniff out, and then snuff out, any threat to his control of the party.
That includes the 43-year-old DeSantis, who has told friends he believes Mr. Trump’s expectation that he bend the knee is asking too much. That refusal has set up a generational clash and a test of loyalty in the de facto capital of today’s G.O.P., one watched by Republicans elsewhere who’ve ridden to power on Mr. Trump’s coattails.
Already, party figures are attempting to calm matters.
“They’re the two most important leaders in the Republican Party,” said Brian Ballard, a longtime Florida lobbyist with connections to both men, predicting Mr. Trump and Mr. DeSantis “will be personal and political friends for the rest of their careers.”
Mr. Trump’s aides also have tried to tamp down questions about the former president’s frustrations, so as not…