I think a lot of the talk about being more polarized today stems from the fact that we seem more divided by geography, both in terms of North v. South and urban vs. rural, particularly looking at the direction of the Senate in recent years. But certainly Reagan was a very polarizing figure in 1980 on an individual level. I'm not sure what your point it.
Anderson ran as a moderate in 1980....remember, he was a Republican. And I'm sure Reagan got a much higher % of the Democratic vote than Bush got.
I think "polarized" in this case refers to one's presidential vote corresponding very strongly to one's state, one's Senate vote, one's party ID, one's views on the war, one's view on gay rights, etc. There was a lot more cross-party voting in 1980 than today. And a lot more people voted for Democratic Senators and Congressmen while voting Republican for President in 1980 than today.
The 1980 election actually had a fair amount of straight ticket voting, thats why the GOP gained 12 seats in the senate that year and 30 seats in the house. Had the GOP the funds to compete in 1980 at the local level, it may have had close to 210 house members.
As for Anderson, one could argue many of the issues he ran on then were to the left of Carter. Anderson did his best in counties that had highly educated and secular whites, the kind of counties such as Marin County in CA, King County WA, the Boston suburbs, that Kerry did his best in.