This was the week Mitt Romney should have sealed the Republican presidential nomination. He was expected to win Tuesday's caucuses in Colorado, to win or tie in Minnesota and to do credibly well in Missouri. Instead, the former Massachusetts governor managed to lose all three contests to Rick Santorum, a candidate who has spent most of the campaign stuck near the bottom of the polls.
Romney has done well in states such as New Hampshire and Florida, where moderate voters make up a significant share of the Republican electorate. But conservative states just aren't having him yet, especially those that hold caucuses, which tend to draw only the most committed voters.
At this point, the GOP looks more like a collection of warring tribes than a cohesive political force. Fiscal conservatives don't have much use for social conservatives. Libertarians and moderates don't get along with either camp.
"We are factionalized now as a party," lamented Rep. Michele Bachmann, R-Minn. "We have to come together."
She's right. Why? Because the long and relentlessly negative campaign is making all the GOP candidates less likable to independent voters, who will probably determine the outcome of this fall's general election.
An ABC News-Washington Post poll released this week measured the phenomenon, asking voters: As you learn more about these candidates, do you like them more, or like them less?
In the case of Romney, 52 percent of voters said the more they knew about him, the less they liked him. That's not surprising after a month of unflattering revelations about Romney's business career and his investment accounts overseas, but it's not a good sign.
Newt Gingrich fared even worse: 60 percent of voters said the more they learned about him, they less they liked.
When the survey was conducted, the pollsters didn't think enough of Santorum's chances to include his name in the question. As recently as last month, 20% of Americans said they had never even heard of the former Pennsylvania senator. But among Republicans who recognized Santorum's name, the general impression was positive; unlike Gingrich, he does not draw automatic opposition from a big chunk of the GOP electorate. That can be attributed in part to the fact that up to now the other candidates haven't needed to attack him.
Now, in the wake of his victories, Santorum will be on the receiving end of some serious hazing at the hands of the Romney campaign.
It's already begun. In recent days, the Romney campaign dispatched one of its spokesmen, former Minnesota Gov. Tim Pawlenty, to warn GOP voters that Santorum is a Washington insider who liked the place so much that after he lost his Senate seat, he stayed in the hated capital as a lobbyist.
But Santorum, whose choirboy demeanor doesn't conceal his taste for bare-knuckled combat, struck right back. "Gov. Romney -- 'Mr. Outsider' -- was for government takeover in healthcare, was for government takeover of the private sector in the Wall Street bailout," Santorum said Wednesday on CNN. "So Mr. Private Sector was Mr. Big Government."
In the coming mud fight, there are reasons to expect that Santorum will make a better showing than Gingrich. But mud fights, whatever the outcome, don't tend to build party unity.
In a Fox News poll last month, GOP voters ranked Santorum first among the candidates as a "true conservative," well ahead of Romney and Gingrich. And in the ABC-Washington Post poll, they ranked him roughly on par with Romney as "honest and trustworthy" -- well ahead of Gingrich, whom only 7 percent considered the most honest. (Even most Gingrich supporters said they didn't consider him the most trustworthy candidate.)
Conservatives who want an alternative to Romney are still looking for the right champion. The month ahead is Santorum's chance to win that role.
Arizona and Michigan hold primary elections on Feb. 28; Romney is expected to win Arizona easily, but Santorum is taking his blue-collar message to Michigan to try to stage another upset.
The most decisive day of this bitter campaign, though, is likely to be March 6, Super Tuesday, with seven primaries and three caucuses. Romney is expected to win Massachusetts and Virginia, and Gingrich hopes to win his native Georgia.
But Santorum has a shot in Oklahoma and Tennessee -- and all three are campaigning fiercely for the most important swing state on the list, Ohio.
After Super Tuesday, the question will be: Which of the non-Romney candidates should drop out, Santorum or Gingrich?
Republican strategists, weighing the candidates' strengths on the map, in campaign organization and in funding, believe Romney is still likely to outlast his opponents. But it will take him longer, cost him more and do more damage to his standing than a short campaign would have.
Millions of independent voters are tuning in to this campaign and learning about the potential Republican nominees -- in some cases, for the first time.
And many of them don't like what they see.
Doyle McManus is a columnist for The Los Angeles Times. Readers may send him email at email@example.com.