But the far left is not in power, does not control the Democratic party nor has it really ever been in power. The far right has siezed control of much of the Republican party.
Take 2004 Democratic primaries. You had two candidates that were what would be in the far left camp. Kucinich and Sharpton. They didn't even get a sniff within the nomination of the party.
Where is the middle? John Edwards, Susan Collins, Lincoln Chafee, Chuck Hagel, Wesley Clark, Rudy Gulianni, John Kerry, Jim Webb, Bryron Dorgan, Harold Ford.
There is a mix of Dems and Reps. They tend to vote with their parties most of the time but they also show pragmatism at times as well. The extremes of the left and right will call the above people out of the mainstream because they are not the same party or they occassionally work with people on the other side of the aisle.