E.J. Dionne makes an interesting observation about Obama’s pick of Arne Duncan as Secretary of Education.

Because Duncan gets along with teachers unions but is also seen as a reformer, his selection was interpreted as a politically shrewd, split-the-difference choice. But that is not the whole story. Lurking behind Obama’s talk about getting beyond ideology and stale disputes is an effort to undercut the success that conservatives have enjoyed in framing arguments that leave Democrats and liberals at an automatic disadvantage.

To declare that the only test of a politician’s commitment to reform is a willingness to break with unions creates a no-win choice for Democrats. They must either betray long- standing allies or face condemnation as the captives of special interests.

Obama, said Diane Ravitch, an assistant secretary of education in the administration of George H.W. Bush, is trying to “break out” of a definition of reform drawn almost entirely from “the Republican agenda.” That agenda focuses on “being tough on the unions, offering more choices, and pushing for more accountability.” While reformers of all stripes support accountability, this list actually constrains the options for those who would improve the public schools.

Duncan has already made clear that he refuses to abide by the conventions of the current education debate. When the Economic Policy Institute, a liberal and pro-labor think tank, circulated an education manifesto that focused on expanding the services for poor children available at public schools, Duncan signed on.

This seems to me a sharp-eyed take. Obama’s effort to be post-partisan, as it were, is not merely an attempt to split differences or accommodate both sides of an argument. He seeks to change the terms of the argument, just as he did in both the primary and general elections.