Some thoughts:
1) Gun rights advocates should probably stop arguing that more handguns would have a preventative effect. The data are not on their side. The American Journal for Public Health released a UPENN study in a late 2009—unique in that it explored a gun-holder’s safety and/or risk at the time of a shooting—that found “people with a gun were 4.5 times more likely to be shot in an assault than those not possessing a gun.”
2) Representative Giffords was shot while engaging in an event that gets close to the ideal of democracy—the hyper-local, issue-based community meeting. A suggestion: for one week, representatives of both federal chambers, with a member of the opposite political party present and engaged, should hold policy discussions with their constituents. The President and our new speaker, John Boehner, should set the tone by answering questions about health care, the budget, Afghanistan, etc. in front of citizens of Ms. Giffords’ district. Don’t televise it. Don’t beem it over the radio. Don’t tweet about it. Just talk. Rationally. Together.
3) I don’t want to try to glean the motive of a young man who unloaded multiple rounds into that crowd on Saturday. Nor do I want to suggest that his underlying mental health condition (I was one DSM subcategory away from diagnosing him with Schizoaffective disorder simply from anecdotes—tendency to wear bright clothing, persecutorial delusions, etc—about him in a NYT article) can or should wholly explain this crime. But any constituent of a Republican house member should realize what repealing the Affordable Care Act would do to Mental Health support in America. Linked here is a list of provisions that the ACA includes to help reduce the stigma and improve the treatment of psychiatric disorders. Tell your congressperson that we need to not just keep these reforms on track, but continue to explore new ways to improve this specialized care modality.
4) Diagnosis and monitoring remains the toughest aspect to treating psychiatric disorders, so my last suggestion is directed at Google and Facebook: Use all that private profile information, partner with national mental health professionals to establish algorithms that could flag accounts that have profile-updating or search patterns consistent with the behavior of those effected by specific mental illness, and design some sort of outreach to these individuals.