John Cronin

Those who bend the knee vigorously, such as Ken Paxton, the scandal-plagued Texas Attorney General, are rewarded with endorsements.

Those displaying even an iota of independence, such as John Cronin or Bill Cassidy, are ostracized or forced from office.

Even as Mr. Trump builds monuments to himself and tramples Democratic and conservative norms, the Republican-led Congress has shown little appetite to constrain him.

That is why the party's unity is becoming an electoral liability.