Romney won the popular vote in six states, while Santorum won three and Newt Gingrich won one. Political pundits, though, said that Romney underperformed and Santorum overperformed, and that self-identified evangelicals and born-again Christians were key to his success.

Not counting the home states of Romney and Gingrich, Santorum easily won the evangelical vote in three of four states where exit polls were conducted, including in Ohio, which he narrowly lost:

-- In Tennessee, Santorum won 43 percent of evangelicals to Gingrich's 25 percent and Romney's 24 percent, according to a New York Times exit poll of evangelicals of all races.

-- In Ohio, Santorum edged Romney for the evangelical vote, 47 percent to 30 percent, with Gingrich winning 15 percent, according to the Times exit poll.

-- In Oklahoma, Santorum won 37 percent of white evangelicals to the 27 percent each that Gingrich and Romney received, according to a CNN exit poll. (The New York Times did not release an Oklahoma exit poll while CNN's exit poll does not encompass evangelicals of all races.).

Evangelicals comprised 76 percent, 49 percent and 72 percent of GOP voters, respectively, in Tennessee, Ohio and Oklahoma.

Romney won 56 percent of evangelicals in his home state of Massachusetts, and Gingrich won 51 percent of that group in his home state of Georgia. Romney also won evangelicals in Vermont, receiving 39 percent of them to Santorum's 33 percent.

Romney remains the favorite when looking at the delegate totals -- The New York Times' tally has Romney with 415 delegates to Santorum's 176 and Gingrich's 105 -- but it could be a long month for Romney based on the primary landscape, in which a series of states with strong evangelical and social conservative contingents will cast ballots. The Kansas primary will be held Saturday (March 10), with Alabama's and Mississippi's primary and Hawaii's caucus on March 13. After that comes a Missouri caucus (March 17), an Illinois primary (March 20) and a Louisiana primary (March 24).

Romney may be favored only in a couple of those states. Kansas is a state that voted for staunch social conservative Mike Huckabee in 2008 and could give Santorum another victory. Santorum and Gingrich figure to battle for wins in Alabama and Mississippi and perhaps Louisiana -- if both are still in the race by then. Santorum already won the Missouri caucus and is favored in the primary there. Continued...