Totally unscriptural on the part of the pastor.
“1 Therefore I exhort first of all that supplications, prayers, intercessions, and giving of thanks be made for all men, 2 for kings and all who are in authority, that we may lead a quiet and peaceable life in all godliness and reverence. 3 For this is good and acceptable in the sight of God our Savior, 4 who desires all men to be saved and to come to the knowledge of the truth.” - 1 Timothy 2:4
Most scholars believe Nero was emperor at the time the Apostle Paul wrote this.
We ought to be praying for Obama, that he be saved and repent from his evil ways, or failing that, that God would lead him away from doing evil to our nation.
Of course, God may choose to judge him, as he did to Herod in Acts 12, but it is not our place, as Christians, to pray for his death.
“1 Therefore I exhort first of all that supplications, prayers, intercessions, and giving of thanks be made for all men, 2 for kings and all who are in authority, that we may lead a quiet and peaceable life in all godliness and reverence. 3 For this is good and acceptable in the sight of God our Savior, 4 who desires all men to be saved and to come to the knowledge of the truth.” - 1 Timothy 2:4
I appreciate you posting that and what you quoted bears repeating one more time. This is the last word of God on our relation to prayer for our leaders, including Barak Obama. We are bound by this last word to pray for the good of all our leaders. Nowhere in the New Testament is their any contradiction of this, nothing authorizing and commanding us to pray for evil upon any man, including Barak Obama. Christians should believe that David was under the Old Law and what was right for him as the Anointed of God is not applicable to us. (Ephesians 2:15, Colossians 2:14)