We don’t need to pray for Obama being a failure, he living proof of AA in America.
Paul puts absolutely no qualifications on his admonition to pray for all in authority, including rulers: "I exhort therefore, that, first of all, supplications, prayers, intercessions, and giving of thanks, be made for all men; For kings, and for all that are in authority; that we may lead a quiet and peaceable life in all godliness and honesty. For this is good and acceptable in the sight of God our Saviour" (I Timothy 2:1-3).
Sorry, but I don't see any back door or escape clause there. Certainly the rulers and kings of Paul's day were vastly worse than anyone we ever have had, or now have, in authority here. Paul says a great deal about how you should pray for such people, but it is all positive, in terms of praying for their wisdom, revelation of the Lord, and so on.
He says in Romans 13:1 "Let every soul be sugmect to the governing authorities. For there is no authority except from God, and the authorities that exist are appointed by God. (2) Therefore whoever resists the authority resists the ordinance of God, . . . ." and so on.
Folks, I really wish that wasn't in there. But I'm not going to deny that it is, or willfully disobey it because I don't happen to like the "authority."