There's one essential point to note here. These attacks are against sitting members of Congress. The Capitol Police and the Secret Service take this sort of thing seriously. I have no idea what they're doing about it, but you have to imagine that an awful lot of these activists are going to find themselves in jail for a long time.

You're absolutely right that Republicans are pandering to the Tea Party wingnuts. The #1 question is the extent to which this will help or hurt the Republicans at the polls in November. This violent Tea Party behavior may well turn off centrists who don't see themselves associating with everything the Tea Party, and by proxy, the Republican Party, has come to stand for. It's unclear whether the Democrats will be able to effectively capitalize on this.