Just for the record, the IRS has been used to target political opponents (and dissenters in general) by every administration since at least that of President Eisenhower. The IRS was one of the main tools of the illegal COINTEL program, begun by J. Edgar Hoover in 1956. Under that program, the FBI used information provided by the IRS to target a wide range of "subversive" individuals and groups under both Republican and Democratic administrations.
During the Nixon administration, the IRS was given lists of (left-wing) activists by the Dept. of Justice, and instructed to audit and harass them. Around 3,000 groups and 8,000 individuals were so targeted, solely on the basis of their political speech.
The Kennedy, Clinton, and both Bush administrations all used the IRS in similar ways.
There's nothing new about any of this. What's actually different about the current "scandal" is that the Ohio IRS office was conducting routine investigations of whether 501(4)(c) organizations were eligible for tax-exempt status. They seem to have been more zealous in investigating groups with "Tea party" or "Patriot" in their names, but it was their legitimate job to investigate applications by all such groups.