I didn't catch the first part of Obama's Tucson speech -- I was scanning channels in search of the Real Housewives of Beverly Hills -- but I thought, from what I saw, that it was a possible "Challenger moment" for the president, which will help him "bond" with the people on the deeper level (as Reagan's remarks did after the Challenger disaster) and could mark a comeback of sorts. It was an exploitative moment, but he exploited it well, for maximum political benefit. That's not a criticism. That's just what presidents do. And if you think there wasn't a great deal of calculation involved, you're mistaken.
Most presidents are presented with one or two bonding opportunities with the American people. Frequently, and sadly, they come at a dark moment. Reagan's remarks after the space shuttle exploded (and his brave way of handling an assassination attempt); Clinton's speech after the Oklahoma City bombing; George W. Bush standing on a rubble pile at "ground zero," megaphone in hand: each forged a deeper emotional connection between a president and the people. This was just such a moment for President Obama. And I think, though it was fraught with backfire potential, and it appeared at moments to flirt with crass exploitation, that he threaded the needle and emerged much stronger.
My prediction: It may have helped him win a second term.