According to my dictionary, a conservative is “a person who is averse to change and holds to traditional values and attitudes.” A radical, by contrast, is someone who advocates “thorough or complete change” and “departure from tradition.”

Which term best describes President Trump?

He’s a radical, of course. At every turn, Trump has challenged our most sacred national traditions: freedom of the press, the rule of law, independent courts, and more. He’s not a conservative; he’s the opposite of one.

So our own challenge, as citizens, is to defend those institutions. It doesn’t matter if we’re Democrats, Republicans, independents, or none of the above. We are all conservatives now, in a dictionary sense. Or, at least, we should be.

But we’re not acting like it. On the GOP side, people who would otherwise indict Trump’s reckless behavior have ignored it. The only Republicans in Congress who have firmly called him out Trump (Jeff Flake, Bob Corker) are on the way out; almost everyone else has turned a blind eye, holding their noses all the while. That’s not leadership; it’s cowardice.

Meanwhile, too many of my fellow Democrats have decided to fight Trump by questioning his legitimacy, not just his politics. And that bears an uncanny echo to Trump himself, who built his White House campaign on the “birther” lie about Barack Obama.

To be fair, I haven’t heard anyone suggest that Trump wasn’t born in the United States. But I’ve heard plenty of people proclaim that he’s not a “legitimate president”—to quote Representative John Lewis—because the Russians allegedly swung the election to him.

Wait, wasn’t it Trump who kept warning on the campaign trail that the election was “rigged”? John Lewis is a genuine American hero, and Trump is a charlatan, but Lewis’s remark was Trumpian to the core. Lewis doesn’t know whether Russian interference decided the election, any more than you do. Saying so—without real evidence—undermines not just our electoral institutions, but also the special prosecutor whom we have charged with investigating the Russian attacks on them. If we already know the answer, why bother to ask?

Ditto for the much-heard claim that fewer people voted for Trump than for Hillary Clinton, so she should be president rather than him. Under our Constitution, the person with the most electoral (not popular) votes wins. You might think it’s time to revise that practice; I certainly do. But there’s a system for changing it, which is outlined in—yes—the Constitution. Donald Trump became President under the process that has governed America since 1787. So if you say he is “Not My President,” you’re not just dissing Trump; you’re saying that the rules are illegitimate when they yield an outcome you don’t like.

Sound familiar? Again, it’s exactly how Trump operates. If a court rules against him, it’s because of the judge’s ethnic bias; if the FBI investigates him, it’s because the agency is in “tatters” and “the worst in history.” And so on.

Then there’s the Twenty-Fifth Amendment gambit, which might be the most Trump-like of all of the attacks on the president. Every time he slurs a word, the blogosphere lights up with claims that he is physically or mentally incapable of holding office.

Please. The charge is based on rumor and innuendo—Trump’s own signature idioms—rather than on fact. And it also undermines the Twenty-Fifth Amendment itself, which allows the vice president and a majority of the cabinet to recommend the removal of a president who is unable to function as one.

If you look at the congressional debate surrounding the amendment, which passed in 1967, you’ll see that it was designed to remove people who were clearly and unmistakably handicapped. Indeed, New York Senator Robert F. Kennedy—brother of the murdered president—warned that the amendment might become a weapon for removing leaders who were physically capable but politically unpopular.

Not to worry, replied Indiana Senator Birch Bayh. “We are not getting into a position ... in which when a president makes an unpopular decision, he would immediately be rendered unable to perform the duties of his office,” said Bayh, a central figure in the campaign for the Twenty-Fifth Amendment.

To be removed, in short, you had to be absolutely and unambiguously incapable—like John F. Kennedy was, in the hours between when he was shot and when he died. That’s what his brother and the other authors of the amendment envisioned. Stretching it to cover Trump ignores that history, which is—again—just the kind of thing that Trump does.

Enough already. Desperate times don’t call for radical measures; they call for conservative ones. So it’s time for everyone who loves our country—and its historic traditions—to rally behind them. If you don’t like President Trump, do what the Constitution says: Vote him out. (And if the special prosecutor finds that Trump colluded with Russia—or impeded justice—impeach him.) The best way to challenge Trump is to double down on our constitutional heritage, even as he makes a mockery of it. And the worse way is to imitate Trump, all in the guise of maligning him.