If Donald Trump wins Florida, is it game over?

The Republican establishment has some potential strategies for stopping Trump, but the clock is ticking.

Donald Trump has a big lead on his GOP rivals in Florida, according to polls. If he wins there on March 15, beating Sen. Marco Rubio in his home state, he is almost certain to be the Republican presidential nominee.

That means anti-Trump forces – the establishment, party elites, other candidates – have a little over two weeks to agree on and implement a plan to stop The Donald.

Also, the plan has to actually work. The reality is that in terms of Mr. Trump, the Republican race to this point has been remarkably stable, even predictable. And negative political ads aren’t magic. Their effect, if any, can be short-lived. Given the persistence of Trump’s support, at this late date it might take a coordinated blitz the likes of which US politics has never seen to stop him.

A new Quinnipiac poll of the Sunshine State sparked these musings. Conducted from Feb. 21 to 24, it shows Trump on top with 44 percent of the Florida GOP electorate, and Senator Rubio in second with 28 percent. Sen. Ted Cruz of Texas lags in third at 12 percent, and Gov. John Kasich of Ohio draws 7 percent.

See Rubio’s math problem? To beat Trump in his home state, he needs all of Senator Cruz’s voters, plus most of Kasich’s. Even if those two drop out after March 1’s Super Tuesday (unlikely in itself), that isn’t happening. Some of those voters would flow to Trump, particularly those who backed Cruz as their first choice. This calls into question the Republican consolidation theory, under which Trump loses once the GOP field winnows to a one-on-one.

Trump leads in every age group in this survey. He leads with moderates, conservatives, and those who dub themselves very conservative. He destroys Cruz with white Evangelicals. He leads among tea party adherents.

Florida is the biggest prize of the GOP primary season, notes Peter A. Brown, assistant director of the Quinnipiac University Poll. It awards 99 delegates on a winner-take-all basis.

“If Sen. Rubio can’t win in his own home state, it is difficult to see how he can win elsewhere,” said Mr. Brown in a statement.

Yes, this is just one poll, and it’s dangerous to read too much into one survey. It could be an outlier. And there is at least some good news for Rubio here, as his 28 percent is easily his best showing in a Florida poll this year.

Maybe Rubio’s emergence as the obvious choice of the GOP establishment will power him up with home-state voters.

But the fact is that all state polls in Florida this year have shown similar results. Trump leads the RealClearPolitics rolling average of major state surveys by a whopping 19.4 percent. So Rubio, and/or Cruz, have a long ladder to climb.

And Trump’s support shows no sign of collapsing. If anything, his polls since late last year have been so predictable as to be almost boring. Remember that brief period in November when Ben Carson led the Republican race? Right after that, Trump climbed from the mid-20s in the RealClearPolitics rolling average of national polls to the mid-30s. He’s pretty much stayed there since.

The HuffPost Pollster polling averages have revealed much the same story. Trump has a committed core of voters who chose him as their candidate early on and have not varied since.

“Donald Trump’s Success Isn’t Surprising If You’ve Been Watching the Polls,” runs the headline on a piece Wednesday by HuffPost polling editors.

So what’s going to cause those polls, after all these months, to suddenly dip downward now?

Here are some suggestions we’ve seen Thursday: Carly Fiorina, and the spouses of this year’s male GOP contenders (besides Trump), get together and make an ad denouncing Trump’s dismissive statements about women. Jeb Bush, and all the other former or current GOP contenders and other party luminaries who want to join in, get together and make an ad saying they won’t support Trump if he’s the nominee.

Those would be unprecedented actions. Maybe they would have a corresponding unprecedented effect.

The following is an underlying problem now for the anti-Trump forces: Something doesn’t just have to drive his vote down; it has to do it fast. A slow deflation might not do it. Trump’s rolling; he might roll to the nomination before he’s stopped.

An ad blitz? Maybe. But negative political advertising affects voter opinions only briefly, and then wears off. That makes sense if you think about it. Voters hear other stuff about candidates – either positive ads or news reports – that moderates negative ad effects.

Trump’s biggest vulnerability may be that he needs to add some voters to win. But as the example of Florida shows, the consolidation theory of how Trump loses is beginning to show some cracks.

Florida votes in 19 days. The opposition to Trump really needs to get to work.