Indeed he is one at that. He is also an actor who plays and portrays a wide variety of characters, some fictional and some depicting real life characters, no matter their political affiliation.
This role is the one of Fred Rogers from Mr. Rogers Neighborhood who was a self proclaimed republican.
I'm not entirely sure about the character from Castaway's political affiliation, if he had one.
Political theatre, films and television programs are intertwined more than we would like to think we know.