Certainly it hasn't worked, and won't work, on automatic pilot. Obviously, the best way to get a message to an officeholder is to vote. Next in impact comes the letter to the editor. All officials are sensitive to the editorial pages of their local newspapers. Then comes the personal letter.
Form letters are a waste of time and postage.
It registers with the receiver. I know of situations in which just one letter has changed the course of governmental action. Length is not as important as passion. This is best illustrated by the shortest letter I've ever received. That was passion and brevity.