They discriminated against conservative groups – primarily any group associated with the Tea Party – leading up to the 2012 election by denying them tax exempt status. The Tea Party gr0ups took the matter to the courts, correctly, expecting justice for being wronged by a government agency with a liberal agenda. However, Judge Reggie Walton saw things differently, and provides one of the most ridiculous rulings and rationales that I have ever seen in my 34 years on this earth. From Politco:

"After the plaintiff initiated this case, its application to the IRS for tax-exempt status was approved by the IRS. The allegedly unconstitutional governmental conduct, which delayed the processing of the plaintiff's tax exempt application and brought about this litigation, is no longer impacting the plaintiff," Walton said in his decision to throw out True the Vote's lawsuit against the IRS.

So let me get this straight…because the IRS later approved the tax-exempt status, after the Tea Party Groups brought the matter to court and after the campaigns were over, they now pay no penalty? How does that make sense in any way? If I beat someone up every day for weeks, then stop when they sue me, by this rationale it's no-harm no-foul, since I'm not currently beating them and stopped after the matter was made public.