196 Americans have given 80% of all Super PAC money.
Adam Rifkin stashed this in Politics!
I went searching on the Web for information that corroborates this.
USA Today reports that "nearly $110 million — more than half the money raised by super PACs since Jan. 1, 2011 — came from just 46 people, businesses and organizations that donated at least $1 million each. Super PACs can raise unlimited amounts of cash to influence elections."