According to the WSJ, "President Barack Obama's re-election campaign has begun discussing whether to attack Republican presidential candidate Rick Santorum and try to define him for a general-election audience, potentially breaking from its focus on Mitt Romney."
I would say no. Don't.
1) While Santorum is leading Romney nationally, as well as decisively in both Michigan and Ohio (but not Arizona, where Mitt's well ahead), and appears to have a ton of momentum right now, Romney still has an overwhelming edge in both money and organization. With the Michigan primary still a week and a half away (February 28), he has more than enough time to narrow the gap. And if he wins Arizona and at least makes it close in Michigan (though a win would hardly be a surprise), he'll be in good shape heading into Super Tuesday (March 6), particularly if he also does well in Washington (March 3).
2) Santorum is weakening himself in the long run with his insistent focus on issues like abortion and birth control. He's waging the culture wars of the
1660s 1990s and is proving himself to be ridiculously out of touch with the overwhelming majority of Americans.
3) Santorum has been able to get to this point not just because he's been a solid candidate, polished and seemingly authentic, and not just because he's just because he's the only credible anti-Romney candidate left, but because he's been able to avoid the spotlight as a result of being so far out of it for most of the race. His recent wins in Missouri, Minnesota, and Colorado were the best things that happened to him in this race but perhaps also the worst. The media are paying attention. And so are the voters. (And so is the Romney campaign, which has turned its attack machine on him the way it did Newt. Newt was crushed by it. Sure, there was more to attack in Gingrich than in Santorum, but the the attacks will take their toll over the long run.) Santorum has what it takes to hold up better than others under the spotlight (e.g., Perry and Bachmann, not to mention Cain), but it's possible that he's peaking now and will only wither from here on out.
4) In large part because he wasn't a serious contender until Iowa, but really until those wins in the three states on February 7, Santorum lacks the campaign infrastructure to keep up with Romney. Sure, the money will flow if he keeps winning, and he'll attract the needed expertise, but it's probably too late.
5) Even if he somehow were to win the nomination, Santorum would be no match whatsoever for President Obama. Unless the economy were to collapse, an Obama-Santorum match-up would likely result in a landslide victory for the president, both Electoral College and popular vote. Even with the deep divisions between the two parties, even with all the virulent rage on the Republican side, wouldn't a 60-40 Obama victory be possible, with Santorum only winning the Deep South and isolated right-wing states like Utah and Idaho?
All of which is to say, it's probably not worth going after Santorum right now. Why bother? It seems like a huge waste of time.