Santorum appears to be embracing the DailyKos-led effort in Michigan:
Bill Ballenger, a longtime Michigan politico and the editor of Inside Michigan Politics, told me he received the call Monday. He said the message used a “crusty, older male voice” that repeatedly referred to “we Democrats” and called on Democrats to cast their vote for Santorum tomorrow because Romney opposed the auto bailout. “It went on and on like this and I kept listening because I kind of smelled a rat,” Ballenger said. “And finally at the very end, in a tagline it says, ‘this call was paid for by the Santorum for president committee.’”
Romney calls this a "new low "but, in 1992, Romney voted for Democrat Paul Tsongas in the Democratic presidential primary. Romney claims he was voting for the Democrat he "thought would be the weakest opponent for the Republican." Meanwhile, Kos is having a grand time:
[I]f Santorum and Romney end up trading charges back and forth about how Michigan turned out, then good! That's the point! This GOP nomination contest is a clown show. Anything that keeps it going, keeps Republicans in a state of chaos, and keeps Obama looking better and better in comparison is a win for us. And no matter how much Romney might whine if he loses as a result to Democratic crossover vote, remember — we won't be doing anything that Mitt Romney didn't already do.
Ed Kilgore points out that Democrats voting for Santorum today are a mixed bag:
Some Ds crossing over will indeed be tactical voters while some are either vaguely attracted to Santorum or hate Romney so much it’s hard to call their votes truly “tactical” in the sense of cold-blooded efforts to extent the nominating process or produce the weaknest nominee.
The Dish 