Destructive influence in the political process
And here we are again talking about, guess what, SuperPACs. We already talked about how they deeply undermine the democratic process. As you can see in this graph by The Economist there has been already a huge increase in outside spending via SuperPACs etc. in the campaigns this year:

Where does this money go?
Most of it goes towards negative advertisement campaigns and thereby causing more polarity. This is a problem, because political parties are also in need of a consent to bring their politics forward, while the outside groups are not. Moreover, they may not have sufficient political experience. So even if a presidential candidate wins he will have a hard time to create sufficient support for his plans in the future, when his campaign is based on negative advertisement.
And anyhow, shouldn’t we be constructive after all instead of using all these sums to put each other down? This capitalistic “survival of the strongest” process is neither efficient nor beneficial for the society as a whole.