Before taking the stage in Phoenix on Tuesday evening for a campaign-style rally, the president huddled backstage with state Treasurer Jeff DeWit and former state GOP Chairman Robert Graham. Both are considering running against Flake, an outspoken critic of the president who recently published an anti-Trump book, “Conscience of a Conservative.”

Trump ripped the Arizona senator during the brief meeting, calling him “the flake,” according to three people who provided an account of the discussion. Trump also discussed the potential for a primary challenge to Flake and told DeWit and Graham, both of whom have aligned themselves with the president, to get back to him about their interest in running.