Justin Amash used to belong to the Republican Party while serving as a congressman from a reliably Republican district in Michigan.

How reliable is it? Grand Rapids, Mich., used to be represented in the House of Representatives by Gerald R. Ford, who went on to become the nation’s 38th president. If there was anyone who was more “establishment Republican” than President Ford, then he or she has been hiding in the tall grass for generations.

Amash bailed on the GOP this week. He is the lone GOP House member to sign on to the call to impeach Donald J. Trump. He believes Trump has committed crimes against his high office and the Constitution. Yet his formerly fellow Republicans are having none of it. Now, Amash is having none of them.

He is now an independent. Rumors are flying that he will run for president in 2020 — as a libertarian! Well, good luck with that.

Actually, I admire Amash for sticking to his principles. He likely won’t change any Republican minds by leaving the party. There are those of us out here in this vast nation of ours who believe he is right, that the president did commit crimes that have risen (or sunk!) to the level of impeachment.

He isn’t going to place fealty to the president or to his former political party over the principle of adhering to the law and defending the Constitution.

Is this former GOP back bencher going to move to the front rank of politicians? We will need to see how that plays out. My hope is that he does. My concern is that he will disappear.