Ledyard King

USA TODAY

WASHINGTON — Marco Rubio didn't win in Iowa, or New Hampshire, or South Carolina.

And he’s not expected to win in Nevada on Tuesday.

So how long can the Florida senator keep his campaign for the GOP presidential nomination going without finishing first in a primary or a caucus?

The answer, analysts and Rubio's supporter say, is that he can probably afford to stay behind front-runner Donald Trump for another two or three weeks — even through Super Tuesday on March 1, when 11 states hold nominating contests.

“I don’t think there’s anything else he can do,” said Terry Madonna, director of the Center for Politics and Public Affairs at Franklin & Marshall College in Pennsylvania. “If he comes out of (Super Tuesday) at No. 2 with the rest of the field weakened, then I think the race goes on.”

It’s not unlike the long-haul approach to the GOP nomination that Rubio aides have described in recent weeks.

Marco Rubio touts role as unifier in Tenn.

Under that scenario, he won't necessarily win contests over the short term but will stay close behind Trump by snagging delegates in states that allocate them on a proportional basis. As less successful Republican rivals for the nomination drop out, Rubio will attract enough support to take on Trump head-to-head come March 15, when Florida, Ohio, Illinois and Missouri award all their delegates to whoever wins their primaries that day.

Trump leads the delegate count with 67 followed by Cruz with 11 and Rubio with 10. It will take 1,237 delegates to clinch the nomination — a simple majority of the total 2,472 at stake. So theoretically, there’s plenty of time to catch Trump.

Rubio's strategy seems to be working so far.

With New Jersey Gov. Christie and former Florida governor Jeb Bush out of the race, he's emerged as the favorite of establishment Republicans.

Rubio’s narrow secon -place finish over Sen. Ted Cruz of Texas in Saturday’s South Carolina primary has given his campaign new momentum, as the congressional lawmakers and deep-pocketed donors who had supported Bush gravitate to Rubio.

That extra money will be enormously helpful as the number of states in play increases dramatically and Rubio's campaign shifts from town halls and handshakes to fly-ins and TV ads.

But at some point, Rubio must start winning, Madonna said. That means he has to convince the other candidates — Cruz, Ohio Gov. John Kasich and retired neurosurgeon Ben Carson — to drop out to capitalize on anti-Trump sentiment. So far, none has indicated a desire to do so.

More big GOP donors shift to Marco Rubio

Rubio's long-haul strategy also assumes the great majority of non-Trump supporters will flock to him if Cruz and Kasich exit the race. That's not the case, according to Trump.

“These geniuses. They don't understand that as people drop out, I'm going to get a lot of those votes also,” he said Saturday during his victory speech in South Carolina. “You don't just add them together.”

The clock is ticking for Rubio, said Florida real-estate developer Al Hoffman, a former Republican National Committee finance chairman and Bush supporter who's now leaning toward Rubio.

“He can afford (to come in second) for a little while longer,” Hoffman said. "(But) he better do something quick to neutralize Trump.”