Mitt Romney would seem to be on cruise control heading into Tuesday’s contests in Colorado, Minnesota, and Missouri. But he is suddenly facing a few speed bumps.

He could get upended in the Minnesota caucuses, where the latest Public Policy Polling survey has Rick Santorum at 29 percent, Romney at 27, and Newt Gingrich at 22. But that would be offset by the caucuses in Colorado, where Romney holds a 14-point lead over Santorum and a 22-point edge over Gingrich. And while Santorum has a clean shot at the frontrunner in Missouri, where Newt isn’t on the ballot, that primary is just a beauty contest, with no delegates at stake.

Santorum, for his part, has ratcheted up his rhetoric, saying in Minnesota: “Governor Romney is absolutely incapable of making the case against ‘Obamacare’ successfully and therefore greatly damages our ability to be able to win this election.” The Romney camp has punched back, unloading on the former senator’s “long history of earmarks and pork-barrel spending” and recycling some nice things he said about the former Massachusetts governor in 2008.

But Romney has bigger worries than whether Santorum can revive his long-shot candidacy after four lousy finishes. Among a series of findings in Monday’s Washington Post/ABC poll, this one jumped out: “By better than 2 to 1, Americans say the more they learn about Romney, the less they like him.”

Yow. Not a good sign.

It’s a mistake to make too much of any one poll, and maybe the figure includes those who are being influenced by Gingrich’s continued carpet bombing. Perhaps President Obama’s approval rating rising to 50 percent is a blip, along with his growing support, to 47 percent, among independents. And February is awfully early to begin sweating over an incumbent president beating the likely GOP nominee 52 to 43 percent, or 51–45 among registered voters.

Romney’s camp is challenging the survey, calling it “seriously flawed” because the Obama match-up followed several questions on negative controversies involving its candidate. But the overall direction is clear.

Throw in one other statistic—8.3 percent—and Romney’s challenge comes into sharp relief. If the jobless rate continues to drift downward, the central premise of Romney’s candidacy, that only he has the CEO toolbox to fix the ailing economy, is seriously undermined. It’s a simple fact of political life that a cratering economy helps Romney and an improving one complicates the task of knocking off an incumbent. (Exactly two have been ousted in the last three decades, in 1980 and 1992.)

Yet another flashing yellow light for the Romney operation is turnout. His 50 percent win in Saturday’s Nevada caucuses was quite impressive, even with a boost from the local Mormon population. But fewer than 33,000 voters showed up, compared with 44,000 four years ago. It’s hard to argue that Republicans are bursting with enthusiasm for this field.

As for Gingrich, who’s served notice that he intends to spend the month of February ripping Romney, he has been taking a beating in the press. Last week, says the Project for Excellence in Journalism, 67 percent of the campaign coverage focused on Romney, while Gingrich was a significant presence in 48 percent of the stories examined. Santorum and Ron Paul trailed with 6 percent. For most of the previous three weeks, Newt drew about as much media attention as Romney.

That is the nightmare scenario for Gingrich—that his campaign ends with a whimper. If Santorum does well on Tuesday, he could reemerge as the conservative alternative to Romney, with considerably less baggage. But even if Santorum struggles, the press could just lose interest in Gingrich if Romney is viewed as the de facto nominee. In a time of tight newsroom budgets, fewer journalists have traveled to Nevada, Colorado, Minnesota, and Missouri, making the campaign feel more remote.

In the delegate race, we’re barely out of the first inning, with Romney at 101, Gingrich 32, Santorum 17, and Paul 9. But primary contests are a game of momentum and perception, and as long as Romney looks unstoppable, he’ll continue to be treated as the nominee-in-waiting.

While the Romney team would love for this to be over tomorrow, allowing him to start raising money for the fall, the lack of a contest carries a real downside. The excitement of Iowa, South Carolina, and Florida kept Romney at the forefront of the news. A primary snooze-a-thon would mute his coverage at a time when the president, who chatted up Matt Lauer at Sunday’s Super Bowl, can command the stage anytime he wants.

Romney still has to rebuild his image from the likes-to-fire-people, not-concerned-about-the-very-poor, 14-percent-tax-rate figure who emerged in recent weeks. That’s hard to do when the campaign is oozing along at such a low ebb. Unless Tuesday’s results shake up the race, Romney will increasingly shift to a long-term strategy against a president with suddenly reviving poll numbers.