If we look at actors who actually ran for office and won (not actors who ran and lost or who were merely talked about as potential candidates) it seems Republicans (Reagan, George Murphy, Fred Thompson, Rex Bell, John Davis Lodge, Arnold Schwarzenegger--though of course he was ineligible to be POTUS--Fred Grandy, Robert Dornan, Sonny Bono, Clint Eastwood) clearly outnumber the Democrats (Ben Jones, Al Franken, Helen Gahagan Douglas, Sheila Kuehl, and Will Rogers, Jr.) Note that all the Democrats I named except for Jones and Franken won in Los Angeles area districts.
I don't think the paucity of Democratic actors getting elected outside southern California is a coincidence. As I once wrote in soc.history.what-if, "Democratic actors are vulnerable to the 'Hollywood liberal' stereotype, whereas a Republican actor-politician has the advantage of defying that stereotype ('casting against type')"