Impeachment is about to make everything worse. If our politics seems overheated, our institutions beleaguered and our public debate degraded, just wait until we are in the midst of the impeachment debate.

Dems have had an impeachment itch they have been desperate to scratch ever since President Trump took office. For them, Ukraine is equal parts a genuine outrage and an excuse, the release valve for three years of fear and loathing.

Rather than conduct himself as if he is aware that a hysterical ­opposition is eager to impeach him as soon as it finds a reason, Trump has embraced constant provocation. He has shown little interest in distinguishing between himself and the high office he holds. Though we need to learn more, there is clearly an impropriety in his handling of Ukraine.

If he had only urged Ukrainian President Volodymyr Zelensky to cooperate with Attorney General Bill Barr on the probe related to the beginnings of the 2016 Russian investigation, it would be completely appropriate (the president reportedly pushed other countries to cooperate, as well). Or, if the story only involved Rudy Giuliani poking around in Ukraine under his own power to find damaging information on the Bidens, it would be standard hard-ball politics. It is the intersection of the latter with Trump’s official capacity as president that is inappropriate.

Enough to impeach and remove him? Presidential-level diplomacy always involves horse-trading, and this surely isn’t the first time a president has prodded an ally to do him a favor in his political ­interest. The risk of Trump’s heavy-handed request — an aid package to Ukraine was being held up — was that the Ukrainians would have felt compelled to manufacture dirt on the Bidens. That didn’t happen, and the aid, thanks to congressional pressure, was ­released in short order.

So far as we know, Ukraine lacks the hallmarks of other presidential scandals. There has been no coverup. Trying to keep a transcript of a presidential call from leaking in the absence of any congressional or criminal investigation doesn’t qualify. And once the controversy became public, the White House rapidly released key documents.

Nor is there any violation of law. Trump’s ask of Zelensky wasn’t extortion or a campaign-finance violation under any rational interpretation of our statues. If it were, practically every president in our history would have had criminal exposure.

Unless there is a thermonuclear revelation, impeachment will be an exercise in futility, inevitably ending with Trump’s Senate acquittal. There is tsk-tsking in the press and among Democrats about Republicans holding the line. But GOP senators, by and large, are going to end up where their voters are.

You can’t expect Republicans to be told, falsely, for two and half years straight that some conspiracy with the Russians was going to be uncovered imminently and then accept at face value a five-alarm interpretation of Ukraine.

Democrats can point to the precedent of the Clinton impeachment. Then again, if Trump had flagrantly and repeatedly perjured himself, he would have been impeached long ago. The lesson from the 1990s is, yes, you can impeach in the absence of any real hope of convicting in the Senate, but it’s a lot of trouble to go through for ­basically a censure vote.

If Trump were for some reason actually removed on anything like the current universe of possible evidence, it would create a crisis of legitimacy at the heart of our government. Think of what Britain is going through with Brexit, only worse. Tens of millions of Trump voters would feel cheated and disenfranchised, and the roiling populism that Trump tapped into would grow stronger, not dissipate.

Congress has shown before that it’s possible to conduct a big, news-dominating investigation without impeachment proceedings; it’s what it did during the Iran-Contra hearings in President Ronald Reagan’s second term. But impeachment is the verdict that Dems have always wanted, and any offense will do.

Twitter: @RichLowry