Remember: Al Qaeda's ultimate goal is to restore the caliphate (the Islamic form of government that would preside over the community of believers) and expand Dar al Islam ("Abode of Islam"). Reaching it requires a long war against all – Muslim and non-Muslim – who don't share its extremist Wahhabi worldview.
Al Qaeda, though, has struggled recently to recruit volunteers for this jihad. While bin Laden retains significant support as someone willing to stand up for Muslim concerns, most Muslims abhor Al Qaeda's terrorist methods whose primary targets are innocent noncombatants.
But an apostate as head of the United States could change this equation. It would be a propaganda boost for Al Qaeda's mission. All one has to do is read Al Qaeda's public statements to recognize how frequently it makes baseless apostasy accusations against fellow Muslims who challenge its message or actions.
That's why Obama is bin Laden's dream candidate.
Once branded as an apostate, President Obama would face enormous difficulties in the foreign policy realm, especially in the fight against terrorism.
He's caught between a rock and a hard place. If he softens the US strategy against Al Qaeda and its ideologues, his apostasy might be an afterthought for Al Qaeda. But if he acts firmly in America's national interest to defeat the terrorist threat, he'd be vilified in an Al Qaeda propaganda campaign for reneging on his "true identity."
Furthermore, his administration would struggle to positively engage the Muslim world, where Islam isn't just a religion, it's the way of life. Conservative Muslim populations that are riddled with poverty and low literacy rates can be more readily swayed to join the cause against the "Great Satan" (the US) if their imams and mullahs shout that it is led by an apostate.