Neo-conservatives favoring the death penalty should vote to re-elect Obama in 2012, even if, or particularly if, Rick Perry is the opposition.  Rick Perry has only overseen the executions of about 250 Texans, all of whom were tried and convicted under the ordinary “due” process of law.  Obama kills without even needing a trial or conviction, as the New York Times reports:

WASHINGTON — The reported killing of Anwar al-Awlaki on Friday, an American citizen hit by a missile fired from a drone operated by his own government, instantly reignited a difficult debate over terrorism, civil liberties and the law.

 The Obama administration had long argued that Mr. Awlaki, 40, had joined the enemy in wartime, shifting from propaganda to an operational role in plots against the United States, and last year it quietly decided that he could be targeted for capture or death like any other Al Qaeda leader. It was unclear whether the same formal determination had been made about another radicalized American who may have been killed in the same strike, Samir Khan.
This should make things clear for all to see.  There are no such things as moral absolutes.  There are only situational ethics, and those ethics turn on what the entity doing the moralizing believes is in its interest, and that which it also has to the power to accomplish.   Thus there is no ethical inconsistency with the US requiring the due process of law before depriving its citizens of life, liberty or property, while at the same time summarily executing two of those citizens, so long as it is remembered that in both instances, “moral” is whatever benefits the survival and propagation imperatives of the organism that is the United States (according to its own internal calculus), and “immoral” is whatever doesn’t. 
And please, never mind the legal arguments.  Law was never about morality, just practicality, and as a practical matter, the US can and will do damn well what it pleases so long as it is the most powerful organization in the world.  Save the legal arguments for someone else.  I’ve known for over twenty years that legal arguments are nothing but after-the-fact sophisticated rationalizations for doing what was desired and intended all along. 
But listen up kids.  Are you American citizens?  Then don’t get crosswise with your government.  It may just decide to kill you.  It most emphatically could not care less if in doing so it violated any of your putative constitutional rights, so long as it believe killing you was in its best interest.   That’s the moral of this tale.