Ron Brownstein on the mirror-image strengths and weaknesses of Romney and Santorum:
If anything, though, Tuesday’s results dramatized the inability of either candidate to consistently expand beyond the beachheads of support they have already established. In the most competitive states, Romney continued to struggle among the key elements of the party’s populist wing, particularly evangelical Christians, strong tea party supporters, working-class voters and voters who consider themselves very conservative.
In mirror-image fashion, after Tuesday night’s results, Santorum still has not carried more than 31 percent of Republican voters who do not consider themselves evangelical Christians in any state. (He reached that peak in Oklahoma.) Meanwhile, Romney has now carried a plurality or majority of those less religiously conservative voters in every state, except Oklahoma, where the exit poll showed him falling just short of Santorum. Even in Tennessee, Romney routed Santorum among the roughly one-quarter of voters who did not identify as evangelicals.