Here is an Op-Ed by Bruce Ackerman and Oona Hathaway from the Washington Post. It discusses current negotiations between the Bush Administration and Iraq over establishing a new status of force agreement. Democrats claim (quite plausibly) that Bush is pushing language that amounts to a security guaranty for the government of Iraq. Democrats claim such an agreement would bind future presidents to continue the current policy of large force occupation. I think the Op-Ed and most debate on this issue is missing something.
Forget about the validity of the claims, and consider how easily a presidential candidate could kneecap such a contract on their own by simply announcing their intentions with respect to Iraq. Put out a statement saying that any promise of a long term security guaranty by Bush isn't worth the paper it's printed on, and that if elected you would on the first day order a bottom up policy review of everything in force. I understand that Iraq policy is toxic waste so long as Bush is in office, but that ends when the new person comes in. Whoever it is, they should not be allowed to blame bad policy on ghosts.