Newsom and DeSantis clash in a combative, unusual debate.

Gov. Ron DeSantis of Florida and Gov. Gavin Newsom of California sparred in a surprisingly lively debate on Fox News, disagreeing over taxes, immigration, crime, guns, abortion and Covid in a clash that felt at times like an alternate-reality interlude during the 2024 presidential race.

Mr. Newsom used the platform to burnish his standing as a future national figure for the Democratic Party while Mr. DeSantis took swings at his Democratic counterpart with the kind of unrestrained verve that has been missing from his Republican primary debate performances. The clear goal for Mr. DeSantis was to reinvigorate his flagging candidacy against the front-runner, former President Donald J. Trump.

“By the way, how’s that going for you, Ron?” Mr. Newsom snapped. Mr. DeSantis forced a smile but didn’t speak, as Mr. Newsom continued, “You’re down 41 points in your own home state.”