That's a hard one...
Lets see, total decimation of states rights and using slavery to justify a war based on federal control and political gain vs. using the "freeing the Iraqi people from a dictatorship" excuse to justify a war based on world power and political gain...
Hrmn... it seems like a toss up to me.
Both presidents preyed off of emotions at the time, and immediate gratification for favor from the masses, and history loves Lincoln for it, well... unless you actually do some studying. Maybe history will look as kindly upon GW.