Several Republicans close to the campaign and to the governor have told The Times over the last 24 hours that they are now convinced it’ll be Mr. Pence.

Mr. Bopp, also a member of the convention’s rules committee, told The Times that the “rally made it a 95 percent probability it’s Pence.”

Mr. Pence, who is little known nationally but highly admired in conservative circles, also made a telling private call to Mr. Cardwell, according to a Republican close to both men.

In the call the governor told Mr. Cardwell to delay his planned Tuesday departure to Cleveland for a Republican National Committee meeting, saying Mr. Cardwell needed to be sure to attend an Indianapolis fundraiser featuring Mr. Trump and Mr. Pence.