Bachmann up, then down.
Perry same. Cain same. Gingrich currently up... but for how long?
Answer: IT DOESN'T MATTER.
First, let's be clear: Debate performance is NOT the most important tenet of this year's race. In the end, the performance in the primaries, ONCE we get past New Hampshire, will be the REAL race.
If you were to look at this as an Indy 500 race, all a debate proves is not who is going to win, but who has the "pole" position at the start of the race. Keep in mind that for candidates whom were NOT the sitting president (for a second term) or a vice president (directly from his current VP position), the Iowa and New Hampshire winners did not necessarily win the nomination in the majority of primaries for both democrats and republicans.
What the debates HAVE done, if you have noticed, is see how the candidates act. Some are more polished, some more nuanced, but it is refreshing that we have seen how many of the candidates will project themselves if president.
But the bottom line: debates will NOT change anyone's mind. The iconic statement, "Talk is Cheap", is just as much part of the debate process as a typical conversation in a biker bar. What REALLY happens is how the candidates get their convictions out during the primary process. Even the media won't be able to spin it this time around, because the primaries are the least likely place for national media to work its democratic bias.
One key factor: More people are undecided than are in favor of Romney, which does NOT bode well for him, no matter how sophisticated his ground game is in the states. But rest assured the debates were ONLY the exhibition season. Pole position is decided in Iowa and New Hampshire, and then the race will truly be underway.