The Clinton machine is back to their winning ways. As Newt Gingrich correctly pointed out Obama is being dragged into the political mud, which is a place where the Clintons are very comfortable and can win.
When Newt Gingrich was a very successful and popular speaker of the House, he was brought down with similar tactics. It's very simple. You get your opponent to spend all of their time responding to attacks rather than espousing their ideas. Gingrich fell for it hook, line and sinker. It got to the point where he was actually having daily press briefings in which he spent the entire time denying the constant barrage of criticisms and accusations. If you can get your opponent to spend an entire debate explaining and re-explaining what they meant by a single sentance, you've got 'em.
The Clintons on the other hand, don't fall into that trap. When they are accused of wrong doing, even when it's undeniable, they spend just a few words, if any on denial and then go right into their pitch.
Obama has spent the past week or so trying to explain what he meant when he seemed to compliment Ronald Reagan and the Republican Congress. He could easily just have said, "It's true, not everything the Republicans do is wrong" and then got back on his own message. Instead he has gotten involved in revisiting every word he's said and trying to make it palatable to Hillary supporters (which is never going to happen). What the public sees is not a new vision of hope, but just another politician trying to take back his words.
Some day someone will figure out that trying to convince your sworn enemy that you're right and they're wrong is a complete waste of time and a sure way to lose an election. Until then, Viva la Clintons?