with people on the other side, but actually assign bad faith, bad motives, really treat them with an tittupynot that they're mistaken, but that they're bad 37. >> that's hard to say. getting good measures that go back over time on that kind of concept is trickier. >> it's not that the other party is so misguided that it serves as a threat to the nation, and it becomes more powerful in their minds. >> professor, you've sustain a look at the american people and have come up with a very different conclusion. how do you get to your place? >> i think there is actually less difference than you might think. i think the pew report is a very fine report. it's a very good study stating the public opinion over the last few decades. but there is some confusion. the title is wrong. it's not polarization but party sorting. if you look at polarization of parties in terms that it has not changed in 30 years. polarization in ideological terms it has not changed since the 70's. moderate is a major category. what has happened, and it's been written about as well, sorting. increasingly liberals are in the democ