Justin Amash

FILE - In this June 12, 2019, file photo, Rep. Justin Amash, R-Mich., listens to debate on Capitol Hill in Washington. The first major third-party candidate is emerging in the contest between President Donald Trump and presumptive Democratic nominee Joe Biden. Amash wants to seek the White House as a Libertarian after switching from Republican to independent last July 4 and voting in favor of Trump’s impeachment. (AP Photo/J. Scott Applewhite, File)