From article:

"In fact, the Johnson amendment has proven to be a dangerous tool, allowing political appointees at the Internal Revenue Service (IRS) to determine when moral issues become political issues — and effectively censor churches and religious organizations with the threat of crippling penalties and loss of tax exempt status.

The IRS is the sole interpreter of ambiguous phrases in the law’s provisions. For example, the law “allows” voter registration and education drives. But what constitutes “evidence of bias” and “favoring a candidate”? Who decides? Whomever the current president has appointed head of the IRS will make the final call. How much scrutiny do you think that urban churches like that of Rev. Jeremiah Wright (Obama’s old pastor) came under over the past eight years? Remember how Obama’s IRS aggressively targeted Tea Party groups for audits. Was the IRS fair to morally conservative churches? I can tell you from first-hand experience: it was not."