This entire article can be found here:
This is the most interesting part of it -
"Polarization also has affected the two parties differently. The Republican Party has drifted much farther to the right than the Democratic Party has drifted to the left. Jacob Hacker, a professor at Yale, whose 2006 book, “Off Center,” documented this trend, told me, citing Poole and Rosenthal’s data on congressional voting records, that, since 1975, “Senate Republicans moved roughly twice as far to the right as Senate Democrats moved to the left” and “House Republicans moved roughly six times as far to the right as House Democrats moved to the left.” In other words, the story of the past few decades is asymmetric polarization.
Two well-known Washington political analysts, Thomas Mann, of the bipartisan Brookings Institution, and Norman Ornstein, of the conservative American Enterprise Institute, agree. In a forthcoming book about Washington dysfunction, “It’s Even Worse Than It Looks,” they write, “One of our two major parties, the Republicans, has become an insurgent outlier—ideologically extreme, contemptuous of the inherited social and economic policy regime, scornful of compromise, unpersuaded by conventional understanding of facts, evidence and science, and dismissive of the legitimacy of its political opposition.””