Not necessarily
Clint actually entered the political arena when he won election as mayor of Carmel. Arnie entered the political arena when he got an initiative passed statewide in California. Rumor has it he may run for governor. Heston was elected as president of the NRA.
In all these cases, these actors actually entered the political process rather than just speak their opinions. I think Rob Reiner did the same thing in the initiative process recently. I have more respect for someone who actually enters the arena than I do for those who only want to snipe from the sidelines. I guess that would include us, too.