I fully agree with both Matt Yglesias and Ezra Klein that Members of Congress are getting bad advice about how to protect themselves in the wake of Tucson. I'm not exactly thrilled about the increased security that's been in place on Capitol Hill (and the rest of Washington, for that matter) over the years...but as Yglesias says, there's a much better case to be made for it, based on both the history of Congress and the consequences of something going wrong.
If, however, Congress wants to do something actually responsible in the aftermath of the attack, what I'd recommend is that they dig out the recommendations of the Continuity of Government Commission, which are gathering dust (including digital dust), and act on them. Tom Mann and Norm Ornstein have been waving their hands and trying to get people to pay attention to their (that is, the commission's) suggestions for almost a decade now, with very minimal results. No surprise; there's very little political mileage to be gained by passing process reforms that have no interest group supporters and, with any luck, would never need to be used anyway. Still, it would be a very good thing for the nation if legal and Constitutional means were in place to deal with various easily imagined emergency situations. First order of business: fix the presidential succession situation (as Yglesias and I have both talked about before, although mine was better titled). The point is that there's a plan ready to go, it seems to me like a solid plan, and a succession of Congresses have ignored it.
Now, can we get real-life politicians to focus on "what happens in case of a catastrophe to the nation?" rather than "how can I marginally decrease the already small chances of a catastrophe befalling me?" Well, given the situation, we can only hope. What I'll do is to cite anyone who rejects Fortress Congress (especially out in the districts) and takes action on continuity issues as personally courageous, and I'll ask fellow bloggers, political scientists, and pundits to do the same.