There may be much Republican hand-wringing over Donald Trump's presumptive nomination to face the Democratic candidate for the White House, but the boastful billionaire says he doesn't care, and it doesn't matter. A growing chorus of senior Republican leaders have joined the "anyone but Trump movement," including 2012 Republican presidential nominee Mitt Romney and the last two Republican presidents, George W. Bush and George H.W. Bush. "Does it have to be unified?" Trump asked about the Republican Party.