Last night's results, while incomplete, are a net loss for Obama's campaign. That shouldn't be confused with a catastrophic loss. The bottom line is that, since Super Tuesday, Obama and Hillary have, on balance, performed more or less as expected--maybe the margins have shifted more dramatically in some states, but Obama was forecast to do very well between Super Tuesday and March 4, while Hillary was favored in Ohio and Texas. Obama came tantalizingly close in Texas, but without an outright win, the campaign goes on, and the ball is back in Obama's court.
The question is how. I think Obama made two mistakes over the course of the last week:
He played it safe.
He played nice.
In doing so, he quit playing to win.
By playing nice, he did not respond forcefully enough to the barrage of attacks from the Clinton campaign. He's done a good job of keeping a positive tone overall. That, plus the pushback Wisconsin voters displayed against Hillary's negative attacks there, may have motivated him to try to stay above it.
By playing it safe, he seemed content to let his momentum ride. Again, there was certainly compelling reason to think that trends seen in earlier states were being repeated.
Obama must now counterattack. It's been observed that many of Clinton's messages-while perhaps helpful to her in the short run-will become liabilities against McCain (experience, Iraq, etc.). Obama's core message: Change versus status quo, hope over fear, remain relevant, and even have some new context (i.e.: the 3am ad). Hillary has opened the door for him to offer the greater contrast versus the current administration, and its would-be heir.
He has the language to do this, and without losing his dignity. As for Hillary's attacks, justified or not, Obama must counter them effectively, as the Republicans will surely launch their own jihad soon. (see, it's easy to deflect an unjustified argument, like the Obama/Muslim thing).