Don Blankenship likes to believe he knows something about rough justice and who deserves it.

“We don’t need to investigate our president. We need to arrest Hillary,” one of his campaign ads proclaims, mimicking President Trump’s crude 2016 rallying cry, “Lock her up!”

Mr. Blankenship, who has a respectable chance of winning the Republican nomination for Senate in West Virginia on May 8, is, in more ways than one, the ideal candidate for the Trump era. He spent a year in prison on charges rising from the collapse of one of his coal mines, which killed 29 people. Mr. Blankenship nurses a deep sense of grievance, and he has no political experience to speak of.

But he does have a natural inclination for one of the most distinctive and defining contributions that Mr. Trump has made to American politics: its sound.

In Republican races across the country, candidates like Mr. Blankenship are parroting the president as they try to prove to voters that they are cut from the same cloth as he is. They recite the Trump lexicon, spouting his trademark phrases and slurs like “Drain the swamp,” “Build the wall,” “rigged system,” “fake news” and “America first.”