According to a new graph released by National Journal, four Senators - two from each party - are almost exactly equally moderate; those from Maine (Collins), Alaska (Murkowski), Arkansas (Pryor) and West Virginia (Manchin?). They are closely followed by the Democratic Senators from Indiana and North Carolina (Hagan), as well as McCain.
The most extreme/radical Senators? For Republicans, the most conservative Senator comes from Idaho, closely followed by South Carolina, Texas (Cruz) and Wyoming. And the most liberal Democrats represent Connecticut, Hawaii and New York. Both Senators from these three states are more or less ideologically the same by the way! So hard to tell which one is the more liberal, Gillibrand or Schumer for instance.
Independent Angus King is equally moderate-liberal as Mary Landrieu by the way. So clearly he's not going to change side anytime soon, as there are plenty of more moderate Democrats than him. Actually as many as 11 I think. And the "socialist" independent from Vermont, Bernie Sanders, is actually more moderate than most Democrats! In fact, about 34 Democratic Senators are more liberal than Bernie. How socialist of him...
See where all the 100 Senators place on the scale here:
http://www.washingtonpost.com/blogs/the-fix/wp/2014/10/02/watch-the-senates-ideological-middle-vanish-over-the-last-two-decades/