I strongly agree with John Bogle's view that shareholders should have the final say in how corporate funds are distributed for political purposes (The Supreme Court Had Its Say, Now Let Shareholders Decide, New York Times Week in Review, May 15, 2011: 9).
But shareholders are not the only stakeholders with an interest in this issue. As a consumer, I have a vested interest in whether the Corporation delivers its largess to causes of which I approve. It is therefore essential that there be complete transparency so that I can direct my purchases to companies whose political donations are only to approved politicians.
Each consumer contributes a tiny amount to the Corporation's cash flow. A small proportion of that cash flow gets diverted to politicians rather than contributing to profit. I should be able to direct whether that proportion goes to a politician, or to profit, or to a charity; and if to a politician, it should go to those of whom I approve.
Getting that enshrined in law will be a long and Quixotic quest.