Nothing will happen.
I anticipate we will see reduced restrictions on gun control actually, as the NRA and its allies push back against the Tucson tragedy. That means no laws requiring gun registration, closing private sale and gun show loopholes, reinstating the ban on extended clips, eliminating open carry laws, better background checks, etc. That’s just not the way gun proponents roll, regardless of the tragedy. After all Columbine had no effect, nor did the Virginia Tech shooter. Why should we expect the Tucson Massacre to be any different.
As for civility, well I expect the result to be similar. Maybe some moderation by a few Republicans (especially those who knew Congresswoman Giffords well) but not from the big boys in the conservative media (Fox, Limbaugh, Talk Radio in general), or from Sarah Palin, or the from newer Tea Party members in Congress and elsewhere. Attacks on Obama and the oppressive “Democratic tyranny” and the “Nanny State” and etc. will resume shortly. Thuggish behavior and violent rhetoric and threats will be even worse next year during the election campaign.
In short, I think this song by Nancy Sinatra sums it up quite nicely: