Do you know what Citizen's United is about? It's not about corporation being able to donate money to candidates. Rather it's about them spending their own money, independent of the candidate, and pay for and produce ads! Again all independent. Candidates are NOT allowed to direct them in any wa! If you say no to that, then where does it end? Newspapers can't have editorial sections? Newspapers can't endorse candidates? The Fairness Doctrine? Public funding campaigns? End to opinion newscasts?
It's a slippery slope that nutters like you are to short-sighted to see what it could lead to!
Popular and unpopular political speech needs to be protected. In truth the best way to fight unfair claims is with rebuttal, just like we do here.