Taking the Ball and Going Home
Here's the thing that Democrats just learned in Massachusetts: the base can't save you. In the bluest of blue states, if you run with a progressive agenda and alienate moderates, those alienated moderates will join with the conservatives to kick you out of office. Catering to the base is a losing strategy.
...You might also consider that the voters you're asking them to ignore are their constituents. You know, the majority of the people in their district. The people they ostensibly represent. The people who consistently poll against the various health care plans on the table.
Megan gets it. Pols are supposed to be working on behalf of ALL their constituents, not just the national party base. Those who forget that little detail show a much-enhanced tendency to become ex-pols.
In some safe districts pols have a lot more leeway, but as the Massachussets election shows, it's not unlimited. And in swing districts the candidate who best reflects the majority views of the overall electorate tend to kick ass on wingers who ignore same. This is how Scott Brown reached the Senate, and how Mitt Romney and Kathleen Sebelius became governors.