Trump supporters, please stop this. The man you back has never held office and has not proved himself as a leader of men. You have to include that in your arguments.

It is probably the case this year that most voters see the issue of character as null and void—neither candidate is admirable in that area. As for personality, I suppose it’s a matter of taste. But it must be noted that the most consequential decision of Reagan’s young presidency, when he fired the striking air-traffic controllers, was determined wholly by Reagan’s character—by his guts and willingness to gamble for what he was certain was right.

Trump supporters should be able to make an affirmative case for their candidate without diminishing Reagan or anyone else. You shouldn’t cut down a man you know was great to make him fit your candidate’s size. It is poor political etiquette. It’s also historical parallelism gone mad. Mr. Trump isn’t Reagan, and he isn’t Andrew Jackson either. He’s Mr. Trump. Take him on his terms and make the case.

You can say that the old standards have been swept away, that when it comes to character we’re a changed nation, that Mr. Trump and Hillary Clinton are the result of that decline, and that you pick from among the candidates on offer.