In Oklahoma, by contrast, not only did Santorum's overall win include wins among voters making less than $30,000 and $30,000 to $50,000 categories, but Newt Gingrich soundly defeated Romney among these lower and middle-income voters. As usual, Romney carried voters making more than $100,000 even in the midst of a loss in the state. Tennessee, another state that gave Santorum a win, had a similar pattern, with Gingrich beating out Romney for second place among voters making less than $30,000; in Tennessee, though, Romney fell just short of taking voters earning $100,000 and had to settle for a win among those making $200,000 or more.
Jed Lewison argues that while Romney is moving steadily toward the nomination, he's getting weaker with every win. That's one thing that has to worry his party. His continuing weakness among white working-class voters is another.