Jonathan Zimmerman teaches history and education at New York University. He is the author of “Small Wonder: The Little Red Schoolhouse in History and Memory” (Yale University Press).

Does the Internal Revenue Service scandal conjure “unpleasant echoes” of Richard Nixon?

Sen. Lamar Alexander (R) of Tennessee said last week that it did. So did a host of other GOP critics, who linked the recent targeting of conservative groups by the IRS to Nixon’s use of the agency as a weapon against his “enemies list.”

Liberals quickly replied that President Obama had pledged to root out political bias from the IRS, offering his full cooperation in the ongoing investigation. And whereas Nixon expressly ordered the IRS to harass his foes, there’s still no evidence that Mr. Obama himself even knew about the IRS practice until media outlets reported it.

But both sides are ignoring the sordid politicization of the IRS before Richard Nixon, when Democrats – not Republicans – were in power. Despite what you may have heard, no single party owns an historical monopoly on IRS-related sleaze. And that’s precisely why we all need to be vigilant in guarding against it....