WASHINGTON - President Donald Trump on Monday endorsed former Republican presidential candidate Mitt Romney's run for a US Senate seat in Utah despite Romney often being critical of Trump.During the 2016 presidential campaign, Romney excoriated Trump as a "fraud" who was "playing the American public for suckers.” Trump responded that Romney had "choked like a dog" in his 2012 campaign against President Barack Obama.Trump said on Twitter that Romney "will make a great Senator and worthy successor to @OrrinHatch, and has my full support and endorsement!" Romney announced Friday he would run to replace retiring Senator Orrin Hatch.