Michael Pollan suggested at a recent Grist potluck -- note to editors: for future reference, I make a mean lemon-cilantro chicken -- that we could improve "the situation for food policy" in Congress if we could:

Make the House agriculture committee exclusive. The most important committees in the House -- Energy, Finance, etc. -- are "exclusive," which means their membership has to be drawn from diverse geographical and ideological sources. Ag isn't exclusive, which means it can be (and is) packed with representatives of Big Ag. It's where decent ag legislation goes to die.

Pollan has been advocating this kind of committee reform for a while. In fact, he mentioned the idea in a Q&A follow up to his "Farmer in Chief" manifesto in the New York Times. But I think it's worth pointing out what it does and does not mean to make a House committee exclusive, and why it might not accomplish much. Warning: This post gets fairly deep into the weeds on House committee structure.

Exclusivity does not, according to the Congressional Research Service, require geographical or ideological diversity. What exclusivity does is distribute plum assignments and ensure that individual members don't serve on too many powerful committees -- a member who sits on an exclusive committee can sit on no other committee. Only a few committees are considered powerful enough to warrant such limits (keeping in mind that each party can declare its own set of exclusive committees).

Out of 18 committees, five are exclusive for Democrats: Rules, Appropriations, Ways and Means, Energy and Commerce, and Financial Services. The last two have only recently been promoted, and thus only members who joined since the committees were made exclusive are limited to a single assignment. To put that in context, nonexclusive committees include the still very powerful Armed Services, Budget, International Relations, and Judiciary Committees. And no one is arguing those are packed by region or controlled by a particular interest group.

That said, Democrats could make Agriculture exclusive with a simple majority vote of the caucus (i.e. all the Democratic House members). Should that occur, current members of the committee (if we take the experience with Energy and Commerce and Financial Services as a guide) would continue to serve on multiple committees. Only members added in subsequent congresses would be limited to one. In effect, it would cause no immediate change in the makeup of the House Agriculture Committee. It is new members who would face the choice of Ag or nothing.

And given the powerful interests Midwestern states have in subsidies and farm policy, it seems like their representatives would happily sacrifice other committee assignments -- a seat on the Ag committee means hitting lobbyist and campaign contribution paydirt after all. Perhaps a coveted Appropriations or Ways and Means slot would tempt a farm belt member away, but those rarely come up anyway. Given all that (and considering the fact that Republicans are unlikely to follow suit and declare its membership on the committee to be exclusive), it's hard to imagine exclusivity materially changing anything.

Ezra Klein has discussed the near impossibility of committee reform. He likes to use the example of the House Select Committee on Energy Independence and Global Warming that House Speaker Pelosi created a couple years ago to get around climate change foot-dragger and former Energy and Commerce Committee Chair Rep. John Dingell. It didn't work at the time because House select committees don't have any real legislative authority.

Ultimately, it was Rep. Henry Waxman's thrilling coup to topple Dingell as chairman of his powerful committee that changed the equation for climate change legislation in the House. That required the implicit blessing of Pelosi as well as a majority vote of the caucus. And even then it was only possible because Dingell was perceived as out-of-step with not just the Democratic caucus on the issue, but also the membership of his own committee. It's hard to see that dynamic yet playing out for food policy.

Reform is desperately needed -- and remaking the Agriculture committee would certainly help. But the payoff to anything but a wholesale reorganization is minimal. Meanwhile, the institutional obstacles are overwhelming, if not impossible. The progressive food movement has a lot of work to do politically before it's ready to take on that kind of challenge. It may be best to continue the fight on other fronts.