I disagree that this is a substantial problem, or rather that the emphasis is wrong. Honesty and serious rational inquiry have been lost and that has a serious impact on public policy and therefore my life. I don't care about people being nice to each other in the US Senate. Shout away, but be honest and don't be shallow morons.
I dunno, I'd kinda like to see Senator Wyden from my home state of Oregon punch out Senator Inhofe.
Yeah, I'd quite like to see Tammy Baldwin or the Iraq War veteran who's name I cannot at the moment recall beat down on some conservative bigot, Sumpter-style.
...Who said anything about the US Senate?
We're talking about social interaction.
Admittedly it doesn't explicitly mention politics, but the sentiment is usually angled in that direction. Obviously, there's no evidence that civility in regular social discourse is less evident today than fifty or eighty years ago.