For months, former House Speaker Newt Gingrich (R-Ga.) has been slowly but steadily rising in the polls. Now, two new surveys put Gingrich in first place among Republican presidential hopefuls. Conservative pundits have praised his performances in the GOP debates, and the one-time history professor seems to be the main beneficiary of Herman Cain's drop from frontrunner territory. Still, most pundits are taking Newt's rise to the top with a hefty grain of salt. "There is no doubt that Gingrich will again crash and burn," GOP consultant Tyler Harber tells The Washington Post. Why such skepticism? Here, six reasons:

1. He has too many skeletons in his closet
"The worst thing that could happen to Newt Gingrich's candidacy is a good, close look from the opposition, the press, and primary voters," says Will Wilkinson at The Economist. His biggest liability is probably his two messy divorces, which won't be popular in socially conservative Iowa, says Nate Silver at The New York Times. The former House speaker is also very closely "associated with an exceptionally unpopular institution": Congress. And now, Gingrich's post-Congress lobbying work for Freddie Mac and Fannie Mae — which conservatives blame for the housing crisis — is getting uncomfortably close scrutiny.

2. Gingrich doesn't have enough cash to compete
The GOP nomination "looks out of reach for Gingrich unless he wins an early primary state like Iowa," says Michael Warren at The Weekly Standard. But with his campaign about $1 million in the red, Gingrich can't really staff up, much less run TV and radio ads, in the Hawkeye State. "Gingrich's fundraising has been simply abysmal," and the mass defection of his campaign staff earlier this year is a big part of the problem, says The New York Times' Silver. "The money sometimes follows the polls," but it's still "hard to raise money if you don't have any staff."

3. Newt would never beat Obama
The new CNN poll that shows Gingrich and Mitt Romney tied also shows Romney beating Obama and Newt coming up "significantly short," says Ed Morrissey at Hot Air. That means Republicans have to "wake up and realize" that "to support Newt is tantamount to advocating the re-election of Barack Obama," says Robert Stacy McCain at The Other McCain. "Anyone who thinks Newt can beat Obama is delusional."

4. Gingrich simply isn't likable
The fact that so many Republicans are now backing the "unlikable, disgraced former House speaker" just shows how much Republicans don't want to nominate Romney, says Steve Benen at Washington Monthly. Every time I hear Gingrich's "bombast, it is a joyful noise," Democratic strategist Paul Begala tells The Huffington Post. "Voters came to know him 20 years ago and they hated him." And today, "the more people get to know him, the less they like him." It's obvious why, says Josh Marshall at Talking Points Memo. Newt is mean. He spends much of the debates scolding the moderators. Really, "his emotional center of gravity is contemptuous disdain."

5. He's too moderate for today's GOP
Gingrich's biggest problem is that "the ideas that made him a conservative revolutionary in 1994 make him squishy in 2012," says Dana Milbank in The Washington Post. And his years of "pandering" in D.C. — making nice with Hillary Clinton on health care, supporting cap-and-trade alongside Nancy Pelosi, criticizing global warming alongside John Kerry — put him "in no position to establish himself as the conservative anti-Mitt Romney." Conservatives are already emailing around the "Newt Gingrich Files" detailing his "history of off-message and ideologically erratic comments," says Alexander Burns at Politico. But hey, at least "Gingrich's rise is being taken seriously by his opponents inside the party."

6. The non-Romneys always fade
Many Republicans are desperate to find a viable candidate not named Mitt Romney. But with Gingrich's surge, "the GOP's game of whack-a-frontrunner" is getting downright "comical," says Will Wilkinson at The Economist. Let's hope Newt enjoys his brief stint as the latest conservative alternative to Romney, because like Tim Pawlenty, Michele Bachmann, Rick Perry, and Cain can attest, "it won't last." No one in this weak field has been able to match Romney, and Newt will be no different.