Given the number of candidates with somewhat extreme values who have been successfully elected, the potential for this to backfire seems rather high. Instead, lobbying for run-off elections or other systems that encourage people to vote for whom they want, rather than vote against whom they don't want would be more useful. No more "Gee, I want to vote for the Green Party candidate, but since she's unelectable, that would mean the person I least want will win. Therefore, I have to vote for the 'lesser of evils' candidate." Vote for your top three, and not be penalized. Perhaps in the days before cars, planes, television, telephones, and computers, the Electoral College made sense. But holding onto it for tradition's sake doesn't seem practical. (There are other "traditions" that are now viewed as civil rights violations. So, the government is capable of throwing out traditions.)
If Democrats (or for that matter, any other party) are intent on perverting the system, I'd favor a strategy of trying to get more of the opposition's least opposing candidates in there. In other words, sane people from the opposing party, who if elected, may not be my personal favorite, but is closer to my position than the mainstream of the opposing party.
