In the meantime though, I cast your attention to Andrew Klavan, writing for The Wall Street Journal, and he asserts that The Dark Knight proves that Batman and George W. Bush are practically one and the same. In short...
"The Dark Knight," then, is a conservative movie about the war on terror. And like another such film, last year's "300," "The Dark Knight" is making a fortune depicting the values and necessities that the Bush administration cannot seem to articulate for beans.

But let's look at the comparison to Batman again and why Klavan is so wrong. First, Batman is putting himself on the front line in the war against crime in Gotham City. When Bruce Wayne takes the armor off and we see those cuts and scars, he acquired... nay, he earned... those on his own. President Bush has never been in a real fight. He's a spoiled brat king who sends henchmen (not talking about U.S. military personnel at all, folks) to do his dirty work. Just like The Joker.
Second, from the very beginning of his term of office, and throughout most of his life, Bush has been obsessed with creating a "legacy" that he'll be remembered for. It's a kind of narcissism that fuels the greatest of supervillains. This is not what motivates Bruce Wayne. Wayne is not out for fame or glory, and he can live with the fact that history must never know that he is Batman because that simply does not matter at all to him. What does matter is that he will do whatever is in his power to make sure that no one will ever die... not even those who might most deserve it.
This brings me to another point: Batman's compassion even toward his enemies. We see this in The Dark Knight: Batman doesn't kill The Joker. Heck, if you read the comics at all, you already know that for all his understanding of how twisted and dangerous The Joker is, Batman has never given up hope that the man might be reformed and redeemed. Incarcerated forever for his crimes, yes... but at least with a conscience. Batman does not kill his enemies. He will stop them, and at times punish them when the law fails... but he does not take it upon himself to judge them as unworthy of life. Go read Alan Moore's The Killing Joke if you've never done so, if you want to see what I mean. Does anyone believe that George W. Bush has just as much strength of soul that would keep him from killing his worst enemies and getting away with it, if he could?
Batman wants the people of Gotham to stand up and fight the darkness on their own. Bush wants the people of America to be a superstitious, cowardly lot. 'Nuff said.
I'm going to write more about it in my review, but The Dark Knight is a movie about morality under duress and sometimes having to compromise that. Klavan argues that Batman in The Dark Knight vindicates the neo-conservative belief that Bush must do away with personal rights in order to win the "war on terror" (by the way, nobody who seriously believes in the "war on terror" is worth respecting, in my opinion). He totally missed the point of The Dark Knight here: that though good people are not infallible and do fail at times, good people do at least harbor remorse and regret for not possessing complete wisdom to deal with the world around them. I think this is one of the greatest attributes of conscience... and it's one that Bush and the vast majority of his supporters have never demonstrated.
Which leads to my final point: the possession and abuse of power. In The Dark Knight we see Batman use a technological ability to locate The Joker, though Lucius Fox believes that it is too much power to be given to one man. Batman agrees, and after the need for the power has gone, he gives Lucius the ability to destroy the technology. That could never be George W. Bush. He would keep that power to himself... hell, he darn nearly has that same power already... and tell everyone that he needs it because "the Jokerists are still out there".
Therein lies the greatest reason why Batman and George W. Bush have nothing in common with each other: Batman can say no to power, while Bush cannot get enough of it.
Klavan's essay is the most damned silly thing about The Dark Knight that I've read to date, and is proof of the desperation that Bush's die-hard supporters have been driven to in the final months of their idol's bid to achieve lasting fame. Which made it all the more fun to shoot holes in :-)