Mitt Romney’s attack on Donald Trump was concise and well-written and, by calling the front-runner a “phony” and a “fraud,” hit all the erogenous zones of the anti-Trumpsters. But in the end, the speech flopped because, like so much else of Romney’s career, the message was muddled.

Why was the last GOP nominee shredding his most likely successor? If he feels so strongly that Trump must be stopped, why didn’t he endorse another candidate? And why make the unprecedented attack now?

Three questions, one answer: Romney wants back in, but doesn’t have the nerve to come out and say it. So typical, and another example of what so many Republicans like about Trump. As writer and Fox commentator Monica Crowley put it, frustrated GOP voters “want a street fighter,” and in Trump, they finally have one.

Romney reminded us Thursday that he is a boardroom fighter. He might have been a very good president, and I don’t regret voting for him four years ago. I only regret that he lost an election he should have won.

He was an incompetent candidate, believing he was going to win until the last minute, when he realized his polls were all wrong. He stood mute as a biased moderator sided with President Obama on Benghazi in the crucial second debate. His computerized turn-out-the-vote operation crashed on Election Day.

Romney came close to running again this time, but backed out early last year, a decision he surely regrets. “I would love to be president,” he told Katie Couric. “I just concluded I was not the best person to carry forward the Republican torch.”

He was right then, and he’s still not the right person. Nobody misses him because everybody knows Hillary Clinton would wipe the floor with him.

Yet, save for election or death, there is no cure for the presidential bug, so Romney won’t give up his fantasy. But what he hoped would be seen as a principled stand against Trump was, in fact, a disingenuous and selfish act.

His failure to endorse either Marco Rubio or Ted Cruz is most revealing. Romney’s only hope for stealing the nomination is a brokered GOP convention where nobody has a majority of delegates on the first ballot and he emerges as a compromise. And the only way for that to happen is for both Rubio and Cruz to collect enough delegates so that Trump can’t reach the magic number of 1,237.

If Romney really wanted to stop Trump now, he would have backed one of the two main rivals and urged the other, as well as John Kasich, to get out. A total consolidation of all others against Trump is the only plausible way to deny him the nomination.

But even that might spell disaster for the party. With Trump averaging 35 percent support in the first 15 contests, and with his voters the most committed and enthusiastic, any too-clever-by-half maneuvers that take the nomination from Trump could cause a revolt.

Suppose a furious Trump runs as an independent. Or suppose the bulk of his voters sit on their hands on Election Day. Either way, Clinton probably waltzes into the White House.

Any way you slice it, Romney offers no solution to the GOP’s dilemma. The fears that the party cannot win with Trump are legitimate, but they won’t be resolved by an insider deal or turning to a failed retread.

It’s time that Romney and all the other bent-out-of-shape gentry conservatives face reality. If they don’t have a candidate who can beat Trump fair and square in the primaries, their only other choice is Clinton. And that’s no choice at all.

Check out all the times Trump has unleashed on Romney: