When you say that a corporation shouldn't have the ability to influence elections, I have two questions for you:
1) Do you realize that the NY Times is a corporation? That regularly prints material intending to influence the elections? (I'm certain that you do realize this...and I'm certain that you realize that regulating a corporation's ability to speak politically could have a chilling and eventually tyrannical impact on freedom of the press)
and
2) Do you realize that corporations are easily outspent by unions attempting to influence elections these days? (you will no doubt counter that unions represent the will of the people, not the will of shareholders, but I'll just say that shareholders are people too...the average person with stock in a company is middle class...if you own a 401K you are a shareholder in dozens of companies)
Not to mention the ethical question of "why shouldn't someone who owns a business have the right to speak politically using profits he rightfully earned in legal economic activity?"