How to Define Rick Santorum?

From Kim Strassel, at WSJ, "The Race to Define Rick Santorum":

Troy, Mich.

The Michigan primary, and possibly the Republican presidential nomination, may come down to this one question: Who is Rick Santorum?

Is he, as the former Pennsylvania senator avers, a consistent "full-spectrum" conservative, a pioneer on tough policy, and the only candidate who can provide a clear contrast with Barack Obama? Or is he, as his opponent Mitt Romney argues, little more than a Bush-era big-spender, a political insider?

Michiganders will make that choice Tuesday, as an estimated 1.7 million voters go to the polls. Mr. Romney may be Michigan's native son, but the state has become Mr. Santorum's to lose. His early-February victories in Colorado, Minnesota and Missouri vaulted him to the top of national polls and to a double-digit lead by mid-February in the Great Lake State. Yet Mr. Santorum has been steadily losing ground and enters in a dead heat...

Continue reading.

Strassel makes the point that Romney wins by tearing down his opponents with Blitzkrieg negative advertising, a point William Jacobson has made over and over again.

Meanwhile, Nate Silver has this, "Michigan Forecast Update: Romney's Lead Looks More Tenuous" (via Memeorandum).