Everyone's gotten to the fact that Newsweek's Evan Thomas is factually wrong to say that increased partisan polarization turns people off from politics. It's worth stopping to pause the fact that Thomas had a false, empirically verifiable, CW-reaffirming thesis in his head and a major newsmagazine went ahead and published it without either the author or any of his editors stopping to check the evidence, which would have proven him wrong. Meanwhile, it's a foregone conclusion that nobody involved in publishing this in Newsweek will suffer any deleterious consequences whatsoever. If you repeat the CW, you prosper, no matter what.
Pushing things further, though, I would make the case that polarization is a good thing. Polarization means you know, as a citizen, how to translate political activity -- voting, volunteering, donating -- into policy results. If every Democrat is to the left of every Republican on some issue, then if you want to move the status quo to the left you support Democratic candidates but if you want to move it to the right you support Republicans. Under conditions where there's very little polarization, like the congressional politics of civil rights in the 1950s, you get chaos. Perhaps a certain Democratic incumbent is slightly better on civil rights than his Republican challenger. But the Republican ranking member on some key committee may well be better on civil rights than is the Democratic incumbent. Thus it's possible that backing the incumbent is good for civil rights unless beating the incumbent would cause the balance of power to shift and bring the Republican ranking member into the majority. What's a voter to do? Who knows?
Weak parties make the life of a Washington power broker more interesting. Basically, there's more power brokering to do. There are more horses to trade. There's more dealing to wheel. Politics becomes a fascinating game of three dimensional chess. Polarization is boring. Two parties lay out there programs, people vote, and depending on the election outcomes and the veto points in the system, legislation results. But polarization is simpler for voters. It connects actions to results. And it brings about higher levels of participation as a result.
Photo of the North Pole by Flickr user ianz used under a Creative Commons license