Sen. Marco Rubio (R-Fla.) speaks to the media during a press conference at the Temple Beth El in West Palm Beach, Fla., on Friday. (Joe Raedle/Getty Images)

Rachel Manteuffel works in The Post’s Editorial department.

I am about to cast the most consequential vote in my youngish inconsequential life. Because of a few accidents of history in this crazypants election cycle, and a weird strategic decision I made five years ago, I am about to hold more power in a national election than I have ever had, or will likely ever have again, or really ever should have.

And here is how I am going to wield it: I am going to vote for a man I disdain, an empty suit who is the wholly owned subsidiary of a rich old plutocrat; a man who skitters cockroach-like toward whichever position might keep him safe from having to say what he really thinks; a man whose every stated opinion on any social issue fills me with disgust; a man who has debased himself so much in this race that, by his own admission, he has become an embarrassment to his own children.

That is the man who gets my vote. Why? Because it’s the right thing to do.

Deep breath.

You probably didn’t know there is a Republican primary happening in the District on Saturday. Neither do most people. It’s hardly gotten any publicity, because there are very few Republicans in the District of Columbia: Six percent of the population, to be exact. Only 19 delegates are at stake. This year, though, the crazypants year, their votes matter a lot.

“We haven’t mattered this much,” D.C. Republican Party Executive Director Patrick Mara told me, “since Frederick Douglass was a precinct captain.”

With the ominous rumblings about a brokered convention, every delegate denied to Donald Trump is a big deal. And right now, just before Even-Superer Tuesday, looks like the moment of upheaval in which the part of the party that can’t stand Trump or Ted Cruz realizes it really is going to have to pick one. Or the other. Oh, God.

And now, math: Mara estimates there will be somewhere between 2,000 and 8,000 primary voters. Nineteen delegates is the same number Hawaii gets, but Hawaii had 13,377 Republicans vote. That makes a D.C. vote between 1½ and six times as powerful as a Hawaiian’s. A D.C. Republican voter will have between 40 and 160 times as much share of a delegate as a Texan will.

I am one of those D.C. Republicans, even though my politics are exactly what you’d expect from an urban, unmarried woman who works for a newspaper.

On impulse, I registered as a Republican five years ago when I moved to the city, figuring my actual vote would never matter as much as pretending to be a Republican would. My logic: The greater number of Republicans who appear to live in the District, the more likely we are to get congressional representation from a Republican Congress. A half-million disenfranchised Republicans would just matter a lot more to the powers that be than if those same people were Democrats. Mine would be a world-changing movement, as soon as I persuaded a second person to do it. Which has not happened yet, though not for lack of trying. And so that is how, starting from the conclusion that my actual vote would never matter, I acquired the power of 40 Texans.

Once I realized this, I stopped being a Democrat happily watching things explode over there. To my horror, I actually, accidentally, have some smidgen of responsibility here, and it meant I would have to vote for a Republican. I spent days trying to figure which one.

Moral authorities such as Mitt Romney, The Post’s editorial board and Louis C.K. have declared it the duty of Republicans to stop Trump. Even if Trump is the easiest candidate for a Democrat to beat in November, as some polls currently suggest, I don’t want the rest of the world to watch us get so close to electing a boorish xenophobe sexist who doesn’t seem to care what he’s actually saying about, say, war crimes, as long as the crowd roars in delight. My grandkids are going to ask me what I did in the election of 2016. Frederick Douglass is watching.

So I gotta vote for one of these other clowns. Cruz looks, today, like he’s got the best shot. Eeeuuuuugh, if I may say. But I am voting in D.C., strategically, so I have to decide which one might beat Trump here. Of course there’s no real polling — nobody cares, remember — but Marco Rubio won the D.C. suburbs in Virginia, leading me to conclude he is the choice of Republicans who have probably met Cruz and/or are hoping there continues to be a federal government next year.

The decision I’m hoping #NeverTrump Republicans make in November is the one I’m making now: Vote for someone you despise, rather than blow up the country. I’m voting, actually voting, exercising my franchise, by touching the screen where it says “Marco Rubio.” With as little as possible of the side of my non-dominant pinky finger.