In the latest New York Times/CBS Poll, released Tuesday, Romney was behind Obama by six points, while Santorum trailed by eight. By contrast, the struggling Newt Gingrich trailed by 18 points. Similarly, a recent Pew Research survey found Romney behind Obama by eight points, Santorum was losing by 10, and Gingrich by 18.
As long as Gingrich was his main competitor, Romney had a potent electability argument. But Santorum can say that since he is more or less equally strong against the president, conservatives might as well vote their convictions.
Romney's case for his strength as a general-election candidate was built on a series of once-plausible propositions: (1) a weak economy makes Obama highly vulnerable; (2) this election will thus be about economic and not social issues; (3) the economy needs better management and Romney is the quintessential economic manager; and (4) Romney's business experience solidifies the claims of point No. 3.
The positive trends on jobs and growth may or may not hold - and a crisis with Iran could discombobulate the economies of Europe and the United States. But Romney has to win the nomination now, and the stronger the economy is during the primary period, the weaker the first three pillars of his rationale become.
Moreover, Romney's career in private equity is now, at best, a mixed asset. The attacks on Romney's business background from Gingrich and from Rick Perry created an entirely new dialogue about Romney's wealth, the low tax rates he pays, his foreign accounts, and the larger question of whether Romney can appeal to the white working-class voters who are so vital to a Republican victory, particularly in the Midwest. It's striking that in this swing region, Pew found Obama with an 11-point lead over Romney, and a 10-point lead over Santorum. With numbers like that, a Republican can't win.
