Former Republican Rep. Justin Amash of Michigan left the door open to a potential 2020 run against President Donald Trump on Sunday.<br />The Freedom Caucus founding member made the remark just days after announcing his plans to leave the Republican party.<br />Amash is the only congressional Republican who has called for presidential impeachment proceedings.<br />Amash announced his departure from the Republican party in a Washington Post op-ed published on Independence Day. <br />
