evidence: WASHINGTON — More than 200 Republicans who previously worked for either former President George W. Bush, the late Sen. John McCain, R-Ariz., or Sen. Mitt Romney, R-Utah, endorsed Vice President Kamala Harris for president in an open letter Monday obtained exclusively by USA TODAY. [...] A similar group of about 150 anti-Trump former staffers of Bush, McCain and Romney pledged support for President Joe Biden in the 2020 election. [...] Romney, who voted to impeach Trump as a senator, said he won't support Trump in the 2024 election, but he hasn't endorsed Harris either. Bush, whose family has long been at odds with Trump, did not attend last month's Republican National Convention in Milwaukee, though has refrained form criticizing Trump publicly. As a candidate in 2015, Trump said McCain was "not a war hero." Four years ago, McCain's widow, Cindy McCain, endorsed Biden over Trump.