The 501(c)4 "tax exempt" group is where the big loophole for corporations are people and can donate unlimited money anonymously land. That classification was supposed to be a very narrow group, like a labor union which number in a few hundred requests per year.. The IRS got THOUSANDS of requests right before the elections. The filers could have used a 527 political PAC but donations are TRACKED through those organizations. It was fishy as hell and the IRS was totally correct to hold up the filings for a short time.