President Trump should want a rapid impeachment process. The Ukraine story hasn’t been good for him, and there is only one way out — to get impeached, and the sooner, the better.

The president obviously hates the idea of being impeached. He thinks it’s unfair and is raging against the process with every political and legal argument his team can muster and every insult and countercharge he can make on Twitter. But he doesn’t have any choice in the matter.

Impeachment is baked in the cake. There is no way that Democrats, having opened an impeachment inquiry, although without a vote, can pull up short now. How could they, after touting revelation after revelation, including a supposed “confession” by Trump’s chief of staff?

If there are Democrats in swing districts holding back the House from impeachment, Speaker Nancy Pelosi will have no option but to twist their arms to get to a majority when the time comes.

Trump should want it to come as soon as possible. The phone call with Ukrainian President Volodymyr Zelensky was clearly inappropriate and alarmed all sorts of insiders at the time.

There was, at the very least, the thought of squeezing Ukraine by withholding defense aid, although the ploy might have had multiple motives and may never have been carried out (it seems Ukrainian ­officials didn’t know the aid was blocked until shortly before it was released). And Rudy Giuliani’s ­political and business maneuverings in Ukraine are a worrisome black box.

As impeachment rumbles on, it puts every Trump lapse (Syria, Doral, etc.) in starker relief and places it in the context of the question of whether he should be impeached and removed.

Meanwhile, if support for impeachment is about 50% or a little higher, there is every reason for Democrats to stretch it out. The current process suits their purposes nicely. They interview officials in private and then leak the most damaging parts. There’s no danger of public hearings bouncing the wrong way … because there are no public hearings at all.

The impeachment inquiry also has the advantage of giving the Democratic base what it wants and creating a strong sense of ­action against Trump. When ­Republicans took the House in the middle of President Barack Obama’s first term, they had trouble controlling the expectations of their own base, which wanted immediate results when the GOP had limited power. Impeachment allows Democrats to forestall such a feeling among their own voters, even though they, too, aren’t getting anything substantive done.

This suggests that, as of this moment, Pelosi looks to have judged the politics of impeachment shrewdly, holding off when it still seemed politically premature and striking when the prospect of moving the needle of public opinion presented itself.

Given how impeachment is playing, there is every reason for her to welcome the White House ­embracing the normal strategy in these fights of attempting to frustrate and delay the inquiry. Not only is this standard approach not fully working — former and current officials are talking to House investigators regardless — at the margins it lengthens an inquiry that’s working for the Democrats.

All that said, it is always possible the public will tire of the probe, especially if it reaches past the first month or two of an election year.

What can Trump do about any of this? Absent a mea culpa and promise of full transparency, which aren’t in the cards for temperamental reasons if nothing else, Trump can’t change the dynamic or the timing. But he should be secretly rooting for the rapid arrival of Impeachment Day.

It will be one of the biggest stories of the Trump presidency. Then, like everything else, it will grow old very fast. Impeachment won’t be forgotten, but it will fade into part of the tapestry of endless Trump controversies and outrages, from Charlottesville to his Helsinki press conference with Vladimir Putin.

Democrats will believe they struck a decisive blow against Trump, when they really may have helped him turn the page.

Twitter: @RichLowry