Rick J. Caruso, the wealthy developer, spent $100 million to run for mayor of Los Angeles in 2022. After his decisive defeat, he stepped to the side of the public stage.

But this year, in the weeks and months following the devastating January wildfires, Mr. Caruso has behaved almost as if he won that election. He has been cheerleading businesses trying to reopen, offering advice to homeowners looking for help in rebuilding and assailing the woman who defeated him, Mayor Karen Bass.

As Ms. Bass has faced scrutiny over her response to the fires, Mr. Caruso — with a staff of consultants and a stream of top-quality videos — has sought to present himself as something of a shadow mayor, a business executive who can lead Los Angeles out of this crisis.

“Hi everybody, it’s Rick Caruso, and I’ve got some great news for everybody,” he proclaimed the other day on Instagram, standing on a balcony overlooking the Grove, his high-end mall in Los Angeles. “We’ve got some small businesses that are reopening in the Palisades and Altadena.”

In recent weeks, he has urged administrators to reopen schools that were destroyed by the fires, told homeowners where to go to ensure that the Army Corps of Engineers clears their property and urged people to patronize the few stores that have reopened amid the rubble. The commission of civic and business leaders he created in the days after the fires, called Steadfast LA, has made a show of raising money and proposing how to rebuild.

In many cases, Mr. Caruso is pushing City Hall to take steps it has already taken: Los Angeles has already begun issuing fast-tracked building permits for the Palisades and led extensive campaigns informing people of how to get debris cleared. That Instagram post was put out hours after the mayor visited the same business whose opening he was lauding.