This question has come up countless times and will continue as long as there are divisions in left & right, black & white and up & down. Everyone is responsible for making their own decision if they will voice one ad and not another. There is no one right answer.
Actually…. it’s a matter of personal judgment. Nothing more – nothing less.
I’ve voiced jobs for car dealers, restaurants and hardware stores that I don’t drive, eat or use their products. However, if something is handed to me that I do not feel I can put my heart into it honestly, I simply say, I cannot do that or possibly find someone I know who has no problem with it. That keeps it in “our” ranks, and someone still makes a buck.
If you prefer to voice only Republican or Democrat political spots, that also is your prerogative, and no one should look down their noses at you or anyone else. I find that and other morally defined objections to be worthy of your own personal selection. If you’ll do either, without a worry, I say more power to you. If not, that’s your business and no one else’s. Stick to your convictions.
As an independent voice actor, I have the freedom to choose how I select my work and I’ll stand by that….as will my wallet, whether I can afford it or not.