Judging Social Welfare and Tax Exemption

Organizations under tax reg 501(c)4 are both tax-exempt and don't need to reveal their donors. They also have to …

… according to the law, be exclusively for "social welfare".
… according to the IRS, be primarily for "social welfare:.

The judgment call by the IRS in approving applications for being part of 501(c)4 (and if the organizations are at least 51% for "social welfare") is at the recent IRS scandal as to whether conservative groups were being unfairly targeted for review.  

But the underlying problem is this fuzzy line of how the IRS is allowing groups that aren't exclusively about "social welfare" despite what the law says.

Thus the threat of a law suit to have the IRS adhere to the law — which would remove a lot of that judgment call from the equation. That might exclude some current 501(c)4 organizations, of either political bent … but that's fine by me.