As Republicans spilled into Cleveland on Monday to nominate Donald Trump as their presidential candidate, 2012 nominee Mitt Romney had an equally crucial task: Entertaining his grandchildren at his lakeside summer house in New Hampshire.

U.S. Sen. John McCain of Arizona, the 2008 Republican nominee who has endorsed Trump despite the latter's insults, attended an ice cream party with his wife, Cindy, and volunteers in his re-election campaign in Prescott, Arizona. He also took part in a veterans' gathering.

"Working out of my office in Miami this week," former Florida Gov. Jeb Bush, who dropped out of the Republican presidential race in February, said in an email to Reuters. Bush had been the most active in attacking Trump on the campaign trail and has said he will not be voting for either Trump or Democrat Hillary Clinton on Nov. 8.