Could an American have played Finn Hudson?

Cory Monteith is a Canadian. In his role as Finn Hudson on Glee, he pulls off a combination of innocence, honesty, strength, and naturalness. Topped off with the occasional wonder at how amazing life can be. Could an American have pulled this off? Have we Americans often become a bit too jaded, ironic, or sophisticated for our own good? Too cool? Of course not all Americans are, but I wonder about the available pool of actors in Hollywood.