Once a campaign hits the skids, it’s very hard to come back. Texas Gov. Rick Perry and Herman Cain show why that is.

Perry’s horrid debate performances and tumble in the polls have created a cash problem. The Houston Chronicle reports: “Texas Gov. Rick Perry’s campaign fundraising has gone into a tailspin as a result of poor debate performances and plunging poll numbers, jeopardizing his position as the best-funded Republican presidential candidate of 2012. Perry’s associates and supporters say his campaign has redoubled its money-­raising efforts in the past week to ensure that his campaign will have enough money to survive the first three contests of the 2012 election calendar: Iowa, New Hampshire and South Carolina.” Well, if he finishes in single digits and back in the pack he may not need to worry about South Carolina.

You can understand why donors don’t feel like betting on a horse that’s effectively fallen a dozen lengths behind the leader. There’s something a bit pathetic about it. “One Perry fundraiser, who asked not to be named, said he received 15 RSVPs for a recent event from potential donors saying they might attend. But after a gaffe-marred Perry debate performance, none showed up. ‘The debates have taken a toll,’ the fundraiser said. ‘The national numbers have taken a toll. People see the campaign on a negative trajectory.’ ”

Then there is Cain, who has become a laughingstock. Politico reports: “We posted a video from Fox News yesterday showing Herman Cain asking how to say something [delicious] in ‘Cuban,’ as though that were a language. The Miami Herald has an even more uncomfortable video from Cain’s trip to Florida, in which the candidate seemed flummoxed by — and his staff tried to block reporters from asking — elementary questions about Cuba policy.” According to Cain, a question about easing travel restrictions on Cuba is a “gotcha” question. Well, as one foreign policy report cracked the other day, “For Cain every question is a gotcha.”

As hard as it is to break out of the Republican pack (as Rick Santorum knows) it is proving to be even harder to stage a comeback in this presidential primary. Perhaps there is a fatigue factor. People listened already to Rep. Michele Bachmann (R-Minn.) and then Perry and next Cain. They’re done now, moving on to other contenders. To revisit any one of them seems to be a bit of an ordeal and hardly worth the effort. The formerly top-tier contenders already been tossed into the “discard” pile.

That’s not to say one or more of them couldn’t mount a successful effort in one of the early states. But the task is much harder now that voters have formed their negative impressions. And it sure doesn’t help when, as Cain did, the candidate goes around reinforcing the image that caused his downfall.