In the aftermath of the Senator Blanche Lincoln's (D) primary victory in Arkansas, there's been a lot of back and forth about presidential power. Some claim that the Presidency is weak--that Congress, especially the Senate holds the power. Others, like Glenn Greenwald, argue that Presidents have vast power and influence, but only use it for the things they actually care about.
In the latter scenario, we have Obama campaigning on closing Guatanamo, but then advocating holding those same prisoners without charges in Illinois. We have Obama campaigning on health care reform with a robust public option, but then deciding a public option isn't that important afterall. We have Obama campaigning on carbon reductions to address global warming, but a national speech on energy policy that doesn't even mention those words. The weak-President theorists would say this is just Obama facing the reality of dealing with Congress. I disagree. I think Obama doesn't exercise his powers for progressive values because he doesn't actually share those values.
Bush was able to convince 70% of Americans that Saddam Hussein was responsible for 911!!! Bush was able to convince Americans that two unfunded wars were more important than his ballooning federal deficit. Bush was able to convince Americans that massive tax cuts during an economic boom were a great idea (again, despite the deficit). Bush did all this despite facts that weren't on his side, because this is what he cared about. With the facts on his side, if Obama cared as much about civil rights, health care, global warming, financial regulation, immigration reform, etc. as Bush did about launching wars and cutting taxes, he could move public opinion too.