Offer the aliens citizenship and free health care.

Hmmm.  Now that would really throw them.  Imagine sneaking in a question card into the debate and the moderator asks, "We get a message from an alien invading armada stating they will be here to take our planet in 30 days.  As President, how would you handle that?"

Palin: Well, you know, it would take a maverick, like me and John McCain, to look them alien fellas in the eye and tell 'em: you get outta america Mr. Alien -- you got no green card and you know, with the tax increases Barack Obama and Joe Biden plan you won't want one, because health care costs are so high, and as vice president I would use my legislative power to make sure that gays don't marry but see I have gay friends who are in healthcare so they can sign contracts and visit hospitals.  And you know it takes a maverick to defend America from aliens and Barack Obama so you don't worry! John McCain and I will be there -- you betcha!

Biden: Oh, hell.  First I'd take them to Scranton, PA and show them the hardscrable streets I grew up on and escaped.  I'd show them the concerns around kitchen tables of alien abduction and then I'd tell them about the bill I introduced, with Jesse Helms, because I cross the aisle, in 1989 restricting alien invasions and outlawing abuse of women.  And then I'd tell the nation about the invasion, like Orson Welles did on TV in 1939.  Thats what an Obama-Biden administration would do!