Short on cash and out of states where he can make a stand in primary contests, Newt Gingrich is steering his long-shot White House bid right into the weeds, until he can potentially crash Mitt Romney’s parade.

The former House speaker has adopted a new convention-or-bust strategy that puts him on a course to play party spoiler at the Republican National Convention in Tampa in August. It is a plan that rests on the slim hope that he can curry favor with a GOP establishment that is yearning for the race to be over.

But Gingrich, who must contend with the sometimes complicated Republican National Committee rules as he seeks to amass delegates, sees a hitch that could catapult him to the top spot.

“Mitt Romney doesn’t have 1,144 delegates,” he said, referring to the number necessary to clinch the nomination. “There is no sign yet that he is guaranteed getting 1,144. For some reason, everybody in the establishment is chanting that [former senator Rick] Santorum and I should quit. Well, Romney has to earn this. It’s not going to be given to him. And we have every right to run.”

In switching from a more conventional primary calendar strategy, Gingrich is acknowledging the obvious: With victories in just two states, and drubbings in several others — including Louisiana — the former congressman from Georgia may be out of chances for victory.

“I think you have to respond to reality, and we’ve had, you know, the cash flow was shorter than we’d like it to be,” he said. “So we’re doing the appropriate things to be able to campaign.”

Gingrich’s new course, built on keeping earned delegates in his column and swaying others, will require the kind of message discipline and organization that he has not often displayed. The shift has led to questions about what, exactly, he is seeking by staying in the race and whether he is tacitly acknowledging that his campaign will soon be over.

“Newt’s capacity for self-delusion knows no bounds, and so rather than suspending the campaign, he has developed this ‘big-choice convention’ strategy, which is nothing more than a refusal to admit there are no dates on the calendar in which he can come in any better than third and there might be some primaries where he loses to Ron Paul — again,” said Rich Galen, a former Gingrich aide. “No matter what he chooses to call it, the rest of us are calling it ‘over.’ ”

During the past few weeks, Gingrich’s campaign has been increasingly marginal in the debate about the nomination. In the South, where the candidate had hoped to revive his flagging operation, Santorum soundly beat him, edging him out among conservatives and evangelicals. Santorum and his aides have watched polls that they say suggest that a weakened Gingrich has benefited their team. But they have mostly stopped short of repeated calls for Gingrich to get out. Aides describe the relationships between Santorum and Gingrich and their staffs as friendly, and acknowledge that there have been conversations between the two camps about their common desire to stop Romney.

The conventional wisdom has been that Gingrich’s supporters — dwindling in number as they may be — would flock to Santorum, the other anti-Romney candidate, should Gingrich drop out.

Exit polls suggest that’s not necessarily the case.

In the Mississippi and Alabama primaries this month, for instance, exit polling showed that Gingrich’s supporters value electability more than they value “strong moral character” or a candidate’s status as the “true conservative” in the GOP contest. That is a split that favors Romney

Romney and Gingrich placed first and second, respectively, in both states when it came to voters whose top priority is electability — with Santorum a distant third. That would suggest that those Gingrich electability voters might share more in common with the Romney camp than with Team Santorum.

Santorum has praised Gingrich as a conservative leader who transformed the party, yet has also suggested that his heyday is over.

“We have made it clear that we want Newt’s supporters, but we also want Newt’s thoughts and ideas and to take advantage of the best of Newt,” said John Brabender, Santorum’s senior adviser. “Our campaign is a vehicle for conservatives and tea party types. There is always room for those who share those principles, and we think Gingrich’s supporters fit right in.”

Winning Our Future, a pro-Gingrich super PAC, just bought television time in Wisconsin, which will hold its primary on Tuesday. The ad highlights Gingrich’s conservative record and steers clear of attacks on his rivals.

According to RNC rules, Gingrich must win the backing of five states to even appear on the convention ballot, so he has work to do in persuading unbound delegates to side with him.

“This is the path to his being relevant, but the biggest challenge is to getting delegates selected,” said Soren Dayton, who was tasked with calling unbound delegates on behalf of Sen. John McCain (R-Ariz.) in 2008. “As soon as the delegates get selected, they are going to get bombarded by the Romney and Santorum campaigns, who will argue that Gingrich has no chance of being the nominee.”

Gingrich’s lack of discipline was on display Wednesday night at a campaign event at Georgetown University. The candidate addressed a standing-room-only crowd of about 400 students — many of whom enthusiastically applauded the former House speaker.

But during the 40 minutes he spoke, Gingrich made only a passing reference to the stated theme of the speech — Social Security — and the mention came at the very end of his address, a fact that several students exiting the event said puzzled them.

Gingrich also spent much of the question-and-answer session sparring with students, one a former child janitor who criticized him for his past comments on the topic and another who grilled him about the state of health care in the United States.

Staff writer Chris Cillizza contributed to this report.