[scarface74]

This was just on the front page of HN a day ago:

A bipartisanship bill that would not allow the IRS to offer free tax filings:

https://news.ycombinator.com/item?id=19613725

The Defense of Marriage Act was also bipartisan:

https://en.wikipedia.org/wiki/Defense_of_Marriage_Act

COPA was bipartisan:

https://en.wikipedia.org/wiki/Child_Online_Protection_Act

[int_19h]

PATRIOT Act was also essentially bipartisan (while most opposition was from Dems, more Dems voted for it than against it).

[scarface74]

They were afraid of being labelled unpatriotic. This was during the time where Senator Max Cleland was attacked for being "unpatriotic" even though he lost three limbs in the Vietnam War

[int_19h]

Fundamentally, it's about the fear of not getting re-elected.

And I would dare say that it's probably one of the biggest contributors to all legislation.