Republican Sen. Mitt Romney of Utah said Thursday that he's planning to withhold his endorsement in the 2020 race both in the primary and in the general election, underscoring the uneasy relationship between the GOP's 2012 presidential nominee and the leader of his party. "I'm not planning on endorsing in the presidential race," Romney, who has periodically sparred with Trump, told CNN in the Capitol. "At this stage, I'm not planning on endorsing in the primary or in the general."