Senator No-Show is campaigning hard to return to the Senate after telling Florida voters he wouldn’t run for re-election.

No one who has followed Marco Rubio’s political acrobatics was surprised by this 180-degree pirouette, which occurred soon after Donald Trump humiliated him in the state’s presidential primary. Nor is there any mystery to Rubio’s motive. Being in the Senate is the only way he can stay sufficiently visible to run for the White House again in four years.

When pressed, Rubio says he intends to serve the full term as a senator. Who believes that? There’s only one job he cares about, and he’s going to try again in 2020. Everybody’s aware of his awful attendance record, and that he dislikes the job. “I don’t know that ‘hate’ is the right word,” he told the Washington Post last year. “I’m frustrated.”

The Senate is no fun. It’s creaky and dysfunctional, but you’ve got to actually show up for work if you hope to change it. Rubio had a chance to make history in 2013 with immigration reform, important to his Hispanic constituency, yet he abandoned the fight in the face of opposition from House leaders and rabid talk-radio factions.

The reason for Rubio’s retreat: The issue was damaging his future chances to capture the GOP presidential nomination.

He tried to boost his stock with conservatives when he colluded with Ted Cruz in the 16-day government shutdown, an attempt to defund Obamacare. It was a costly fiasco that sunk the Republican Party to historically low poll numbers.

In the gloomy aftermath, Rubio tried to insist he never favored a shutdown, despite the fact he’d repeatedly voted to defeat “clean” funding bills that would have kept the government running.

Another time that Rubio graced Washington with his presence was a favor to the NRA. He flew in to vote against a bill that would have banned persons on the government’s terror watch list from legally purchasing assault rifles. As a result, terror suspects who aren’t allowed on commercial airlines can still go out and buy an AR-15. You’ll rarely hear Rubio talk about this on the campaign trail.

If nothing else, he’s consistently inconsistent. He says he opposes abortion in all cases, with no exceptions for rape or incest. Yet he voted for a bill that included those very exceptions.

In August he told Politico reporter Marc Caputo that abortions should be denied to pregnant Zika victims who fear birth defects in their unborn. Now Rubio’s campaign is assailing his opponent, Rep. Patrick Murphy, for quoting Rubio’s own words.

During last Wednesday’s debate, Rubio also went after Murphy for supposedly embellishing his biography — a subject upon which Rubio himself is an expert.

For years he’d tell crowds that his parents had fled Cuba as “exiles” when Fidel Castro seized power. He even put it on his official Senate web page.

One small problem: It wasn’t true. Rubio’s parents willingly resettled in the United States in 1956, more than two years before Castro and his rebels rolled into Havana.

Rubio later explained the false tale by saying he’d been relying on “the oral history of his family,” not immigration documents. He gets plenty of practice “clarifying” previous things he has said.

As for why he changed his mind about the sludge-pit Senate, Rubio says he needs to keep the job so he can protect us all from the next president, whether it’s Trump or Hillary Clinton.

This is vintage Marco, the master of political bet-hedging.

Unburdened by principles, Rubio says he’ll still vote for Trump, a man he has lambasted as “a con artist,” “a serious threat to the future of . . . our country,” and an “erratic individual” who can’t be trusted with the doomsday nuclear codes.

How does Rubio reconcile his horrifying portrait of his party’s nominee with his alleged support of the man’s candidacy? He ducks, he wriggles, he triple-talks.

But although Marco’s logic might seem contradictory and complex, he’s a very simple organism. He only does what’s best for Marco, period.

Renouncing Trump would anger Trump voters, and Rubio knows he can’t get re-elected without them. But don’t be fooled — just because he claims to support Trump doesn’t mean he really wants Trump to win.

In fact, Rubio will be vastly relieved if Clinton gets elected. That way he won’t need to challenge a Republican incumbent four years from now. He’ll have Hillary as a sitting target, and a GOP that’s desperate for a unifying candidate.

When Marco says he’s voting for Trump, don’t believe it. He’ll be voting to advance his own presidential ambitions, and putting an embattled Hillary in the White House gives him the clearest path forward.

The Senate is a good place to sit around and wait.

But first you’ve got to show up.

Photo: Republican U.S. presidential candidate Florida Senator Marco Rubio addresses the crowd while campaigning in Toa Baja, Puerto Rico, March 5, 2016. REUTERS/Alvin Baez