I don't see why you would necessarily want to win your party and not the election. I would think that the MVT would want to win the average voter, not the average democrat republican.
But I could see, since voters probably rarely follow the voting record of a representitive, that when voting in congress the rep has a tendency to want to win his party favor there so as to get party support. Also, does the use of voting records make this gap because the reps can only vote yea or nay? Even averaged out over the many voting instances, you can't ever voice moderate or total support, just support or not- thus while you maybe a moderate democrat, you will still likely to vote for all the bills that the party favors. Jason