The conventional wisdom now is that, even with the Republican nomination slipping further and further away, former Speaker Newt Gingrich will fight tooth and nail all the way to Tampa, making life miserable for the party’s likely nominee, former Massachusetts Gov. Mitt Romney.

That scenario certainly is possible, and Democrats surely would benefit from seven months of bloodletting between the party’s establishment and tea party/populist wings.

Maybe I simply like being a contrarian from time to time, but count me as skeptical that Gingrich will fight all the way until June and even beyond, no matter how much bravado and bombast was in his speech Tuesday night.

There is no doubting Gingrich’s contempt for Romney, whose allies have pounded the Georgia Republican repeatedly since he returned from the political graveyard right after Herman Cain’s exit from the GOP race.

Gingrich hasn’t called to congratulate Romney after his two victories, and the former Speaker must be deeply frustrated with his inability to capitalize on his South Carolina victory.

After all, this is a man who thinks big and talks big — a man who, I imagine, thought that he would be his party’s nominee. Modesty and humility don’t come easily to Gingrich, so the thought that he might have missed his opportunity must be difficult to accept. He looks and sounds like a bitter man.

The night of a crushing defeat in a key state was not likely to be the moment Gingrich took a cold-blooded look at his prospects. So it shouldn’t have been surprising that Gingrich’s first reaction Tuesday evening would be one of defiance, as he reiterated his belief that he would be the Republican nominee to face President Barack Obama and promised to take the fight to 46 more states.

But even with proportional representation (required during March contests) preventing the eventual nominee from locking up the nomination quickly, the process makes it difficult for a traditional kind of candidate, such as Gingrich, to remain a factor in the race — especially as long as former Pennsylvania Sen. Rick Santorum remains a viable option for conservatives.

Unlike Rep. Ron Paul, who is promoting his libertarian agenda and has supporters who care more about making their case than about winning the nomination, Gingrich is actually running for president. He’ll need money, victories and a demonstrable path to the nomination to keep his candidacy going.

None of the next seven contests that will select delegates look tailor-made for Gingrich, so it won’t be until March 6, Super Tuesday, that he can show electoral strength. Missouri’s Feb. 7 primary won’t select delegates, but even there, Santorum will be on the ballot, not Gingrich.

A month from now, Gingrich might look even weaker, and the Romney bandwagon could pick up steam as previously undecided voters decide to support the man who they figure will become the party’s eventual nominee.

If that happens, Super Tuesday, with a roster of states less opportune for Gingrich than you might think, could virtually end his candidacy instead of resuscitate it.

Yes, the former Speaker should do well in Georgia and probably in Oklahoma and Alaska. But he won’t be competing in one of three Southern states (Virginia), and his prospects in the third, Tennessee, are uncertain.

Tennessee, after all, is really two or three states in one. Eastern Tennessee is mountain Republican, the kind of place filled with Republicans such as Sens. Lamar Alexander and Bob Corker. Romney should do well there. The rest of the state is more Southern and conservative, though there are pockets of more moderate and establishment Republicans around Memphis and the growing Nashville suburbs.

In battles over the years between “very conservative” and “somewhat conservative” Republican candidates, the more moderate (stylistically, at least) GOP candidates have tended to win. And that has to be worrisome for Gingrich strategists.

If Romney wins two Southern states March 6 — Virginia and Tennessee — and carries Massachusetts, Ohio and a number of other obvious states that day, it will be harder for Gingrich to argue at all persuasively that he has any chance of winning the Republican nomination.

Given the nature of the national media’s coverage of the race, the importance of financial backers in a presidential race and the likelihood that even some of Gingrich’s most loyal supporters will start to suggest that he is doing himself no good by staying in a race that is already over, the ex-Speaker might not feel the same way he did Tuesday night about taking his fight all the way to Tampa.

And if he does remain in the race, he may well adjust his tactics, away from criticizing Romney and more toward simply trying to establish himself as a leader of the conservative cause in the GOP.

Of course, the roller-coaster nature of the race so far means that a few more twists and turns are possible. A surprise revelation or a mistake by a candidate could turn things around. There is no need to count anyone out of the race just yet.

But now the burden clearly is on Gingrich — and Santorum — to change the narrative and the trajectory of the Republican contest. If they can do that, the race can go on for months for one or both of them. If they can’t, they might find that they become less and less relevant — to the media, to their funders and, yes, even to the voters.

Stuart Rothenberg is editor of the Rothenberg Political Report.