santorum
Rick Santorum said Monday if party delegates can choose their preferred candidate at the convention, "they are not going to nominate a moderate Massachusetts governor." Jim Young / Reuters

Rick Santorum got his ticket out of Super Tuesday contests with victories in Tennessee, Oklahoma and North Dakota, while giving Mitt Romney a run for his money in Ohio.

We have won in the West, the Midwest and the South and we're ready to win across this country, the former U.S. senator told supporters at a rally in Steubenville, an Ohio River city near the border with Pennsylvania, Santorum's home state.

Tuesday's contests provided Romney another opportunity to cement his status as the presumptive GOP nominee, but he failed to deliver a knockout blow.

Santorum's victories in the South and one-point loss in Ohio underscore Romney's problem connecting with evangelical Christians, conservatives and less-educated and low-income voters, which can complicate his campaign as the party's nomination fight drags on through 2012.

According to exit polls, Santorum was the clear favorite among the kinds of people who made up Tennessee's electorate Tuesday: white, conservative Tea Party supporters who are mostly Protestant and evangelical.

Santorum had a better standing among Tennesseans without post-secondary education and who make under $100,000 a year. For those who earn more, about a fourth of the electorate, Romney was their choice.

Meanwhile, Santorum beat Romney in Oklahoma, 34 percent to 28 percent. In North Dakota's nonbinding caucus, Santorum scored 40 percent, beating U.S. Rep. Ron Paul of Texas, who was second. Romney finished third.

Given the profile of voters who have flocked to Santorum's campaign, the candidate has momentum going into the next round of Republican primaries -- in Kansas on Saturday, followed by Alabama and Mississippi on March 13.

In Ohio, Santorum did well among voters who believe it's important that the Republican challenger to Barack Obama have a strong moral character and be a true conservative. With that kind of support in a state pivotal to November's general election, he can attack one of Romney's main selling points: that the current front-runner is the only candidate capable of amassing a coalition that can beat Obama.

In his late-night speech Tuesday in Ohio, Santorum said he'll be able to go head to head with the president on the U.S. health care overhaul, something Romney will find tricky to do given his role shepherding similar legislation in Massachusetts as governor.

I've never been for an individual mandate on a state or federal level, Santorum said, referring to the Massachusetts law.

He also accused Romney of being dishonest with the American people about touting that state law as a model for Obama's Affordable Care Act.

Now we find out not only did he do it in Massachusetts, he advocated for it to pass in Washington, D.C., in the middle of the debate on health care, the ex-senator said. We need a person running against President Obama who is right on the issues and truthful with the American public.