The fetishization of bipartisanship in Washington has a cargo-cult quality to it. The worshippers of bipartisanship can see that the bipartisanship has disappeared, but they do not know why. And so they wistfully call for a return to the social mores of the old bipartisan era. This Washington Post op-ed, for instance, offers the hope that if we bring back dinner parties, bipartisanship will follow:

When I worked in the White House Social Office, I was often surprised at how many officials — some serving in the same agency or in the same house of Congress — had never met. Members of Congress and administration officials may be photographed together, but many barely know each other if they’re in different parties. How useful those dinner-party connections seemed, with guests exchanging e-mail addresses and making plans to get together. Once, this cross-pollination happened at dinners all over the city.
Today, however, political purists from both sides openly sneer at the idea of going to a dinner party. Who wants to risk hearing a viewpoint different from his own or be forced to defend her beliefs without the benefit of talking points?

I'm in favor of hearing opposing viewpoints, but I do question the author's understanding of cause and effect here.

Meanwhile, this bit had the opposite of its intended effect on me:

by skipping parties where journalists may be found, politicians are forgoing opportunities to informally shape the debate; for their part, journalists, too, may find it more difficult to savage a politician if they’ve broken bread with him.

Hilariously, she means this as a bad thing. Journalists would savage politicians they don't know, but if they're social pals, they'll pull back. I knew that mildly corrupt insider chumminess was the indictment of Washington dinner party culture. I didn't realize it was also the case in favor of it.