The short version would be since the late 1970s starting with the 1976 election in the House the Republican caucus has steadily moved to the right ever since. It's been a little more uneven in the Senate. The Senate caucuses have also moved to the right. Republicans are now furtherest to the right that they've been in 100 years.
"It is true that the Republicans have moved further to the right than the Democrats have moved to the left. That's absolutely true.
"On the other hand, there doesn't seem to be much impetus on the part of the leadership of either political party to really do something serious about our budget crisis. I doubt very seriously we'll see much improvement.
"People forget how utterly irresponsible our political leadership has been for the last 30 years. ... The current political class of the U.S. just isn't in the same league as Truman and Eisenhower and Adlai Stevenson. You just don't have that kind of leadership now, just when we need it.
-Keith Poole, Egghead at University of Georgia
I don't buy the Truman-Eisenhower nostalgia, but the rest of it about today's wingers is spot on.
The 100 year comparison is also about right, too. 100 years ago, social darwinism was mainstream. Today, it is making a come back thanks to the radical nature of the GOP. The Darwinists had a saying back in the day that "Poverty was the best Policy." That slogan seems to dovetail quite nicely with today's GOP approach toward the lesser amongst us.