Throughout the spring, Gov. Ron DeSantis of Florida and his advisers waved off his sagging poll numbers with the simple fact that he wasn’t yet an actual candidate for president.

Two months in, however, his sputtering presidential campaign is still struggling to gain traction.

Allies are complaining about a lack of a coherent message about why Republican voters should choose Mr. DeSantis over former President Donald J. Trump. Early strategic fissures have emerged between his own political team and the enormous super PAC that will spend tens of millions of dollars to help him. His Tallahassee-based campaign has begun shedding some of the more than 90 workers it had hired — roughly double the Trump campaign payroll — to cut swelling costs that have included $279,000 at the Four Seasons in Miami.

Now, his advisers are promising to reorient the DeSantis candidacy as an “insurgent” run and remake it into a “leaner-meaner” operation, days after the first public glimpse into his political finances showed unsustainable levels of spending — including a taste for private planes — and a fund-raising operation that was alarmingly dependent on its biggest contributors and that did not meet its expectations.