Democratic presidential candidates arguing over why the surge succeeded:

SEN. CLINTON: “The point of the surge was to quickly move the Iraqi government and Iraqi people. That is only now beginning to happen, and I believe in large measure because the Iraqi government, they watch us, they listen to us. I know very well that they follow everything that I say. And my commitment to begin withdrawing our troops in January of 2009 is a big factor, as it is with Senator Obama, Senator Edwards, those of us on the Democratic side. It is a big factor in pushing the Iraqi government to finally do what they should have been doing all along.”
(Meet the Press, NBC, January 13, 2008)
SEN. OBAMA: “I welcome the genuine reductions of violence that have taken place, although I would point out that much of that violence has been reduced because there was an agreement with tribes in Anbar province — Sunni tribes — who started to see, after the Democrats were elected in 2006, you know what, the Americans may be leaving soon, and we are going to be left very vulnerable to the Shi’as.”
(Democratic presidential debate at St. Anselm College in Manchester, N.H., January 5, 2008))