When we set out to write a book about the growing extremism in American politics about 18 months ago, we thought that the 112th Congress was the worst we had seen in our four decades in Washington. However, the fight over the debt limit, the fiscal cliff and the farm bill — and the shutdown of the Federal Aviation Administration — convinced us it has been the worst Congress ever.

Despite its dysfunction, there are also widespread misconceptions about the 112th Congress and what lies ahead. Let's correct a few of them.

1. The 112th Congress was as bad as the 80th "do-nothing" Congress during the Truman era.