Representative Justin Amash, a Republican from Michigan, answers a question during a town hall event in Grand Rapids, Michigan, U.S., on Tuesday, May 28, 2019.

U.S. Representative Justin Amash, a frequent critic of Republican President Donald Trump, said on Thursday that he was quitting the Republican Party, saying politicians have become more loyal to their parties than to the American people.

"Today, I am declaring my independence and leaving the Republican Party. No matter your circumstance, I'm asking you to join me in rejecting the partisan loyalties and rhetoric that divide and dehumanize us," Amash, of Michigan, said in a Washington Post opinion piece published on the U.S. Independence Day holiday.