A Meteor is a 'shooting star'. if it hit's the ground it's then a meteorite. A meteor does no damage, so, no, praying for a shooting star for a President is not illegal, as no one is harmed. It's only a meteorite that could do damage.
As for the current President, if he were hit by a meteorite, it would certainly make him famous. As a second term President, he is looking for how he will make his mark on History.
No one in History has ever been killed by a meteorite, and only a few people have ever been hit by one. That would certainly make President Obama famous, but would probably be no more dangerous than being shot by a BB gun.
We of course would not want to wish any physical damage to this or any other President, Right???