Can't buy it. Romney is their dream opponent, I don't think even Democrats are stupid enough to try and sabotage the guy they know they can beat.
Believe it or not, some Democrats may actually like Santorum. There are many disillusioned Dems out there, I stood next to one at a Tea Party event, and they might want someone they can trust to abolish Obamacare.
When liberal media and the unions make a call for Dems to go out and vote in the GOP Primary for Santorum, it is what it is.
When the Dems state what they are going to do, and then do it, you don’t have to “buy it”. At that point, your choices are reality or denial.