Senator Ted Cruz aggressively worked one ballroom, taking selfies and staying for handshakes with donors and activists for so long the linens had already been cleared.

Mike Pompeo, Donald Trump’s former secretary of state, distanced himself further from his old boss, saying that “personality, celebrity, just aren’t going to get it done.” And Gov. Larry Hogan of Maryland, a longtime Trump critic, welcomed other Republicans now calling out Mr. Trump as an electoral “loser.”

The first auditions for the role of leading Trump alternative consumed the Venetian hotel over the weekend, onstage and off, as nearly a dozen Republican potential presidential candidates tested their strategies and messages days after the former president declared his 2024 candidacy.

One of the most anticipated, Gov. Ron DeSantis, received a raucous reception for a keynote address that outlined how his success in Florida could be a nationwide formula for Republicans. “The state of Florida is where woke goes to die,” Mr. DeSantis declared.