It's not all bad news. When Bernard Sanders was previously in the House of Representatives for Vermont his Conservative Voting Index (that is, the percentage of times he voted with conservatives) was 33%. At that time Teddy Kennedy's was 21%, John Kerry's was 13%, and the late Patrick Moynihan, touted as that great moderate, was 18%.
Maybe to move Congress more toward the center we need to elect more socialists.
You can't compare Senators to Representatives with those indices. There are different bills and different issues.