Donald Trump lashed out at his most likely rival for the Republican presidential nomination, Ron DeSantis.br br During a rally in Iowa, the former president mocked DeSantis for being a "disciple "of Paul Ryan, who he branded a "loser."br br Trump told journalists at the campaign event in Davenport that he regrets his 2018 endorsement of his now-likely rival.br br Florida's governor is yet to officially announce his candidacy for the 2024 run for the White House.