Mayor Bloomberg is frustrated that the New York City United Federation of Teachers does not agree with his plan to evaluate them by test scores. He has been berating the union, as have the city’s tabloids, for weeks.

But now he hit a new low.

He compared the teachers’ union to the National Rifle Association.

Coming only weeks after the Newtown massacre, this is especially gross.

This is reminiscent of the time many years ago when U.S. Secretary of Education Rod Paige referred to the NEA as “a terrorist organization.”

Paige had the good sense to apologize. So should Bloomberg.