It always has been and better always be acceptable. That’s the whole point of the “in effigy” thing, to let the people in charge know you’re angry at them and things could get a bit more real if they don’t straighten up. It’s both part of our right to free expression AND our right to revolution.
As far as your right to revolution, are you planning to violently overthrow the government of the United States of America? What about the right to do so of others, who hold different political views than you?
You will, of course, give your life to defend other American's rights, won't you?