A CONTEST for the least popular arm of the federal government would have many strong contenders.

There’s the soft, cuddly Internal Revenue Service. Also the National Security Agency, America’s Peeping Tom. And let’s not forget the Environmental Protection Agency, seen by many manufacturers as one big, mossy, bossy paean to regulation run amok.

But for politicians, in particular Republicans, another challenger comes into play: the Department of Education.

In a Republican presidential debate during the 2012 campaign, it wasn’t just on the list of “three agencies of government” that Rick Perry famously promised to eliminate. It was one of the two that he succeeded in naming before he stopped short, forgetting the third.

And it finds itself once again in Republican presidential candidates’ cross hairs, all the more so because of Common Core standards, supported by the education secretary, Arne Duncan, and cited by many excessively alarmed conservatives as a federal takeover of curriculum.