Sen. Tom Coburn (R-Okla.) is pushing again this week to stop public funding for the political party conventions, which this year are scheduled to receive $18.3 million — and that’s excluding security, which everyone agrees that the federal government should cover. Coburn introduced his proposal as a bill at the beginning of the week, but he’s now offering it as an amendment to the farm bill that’s currently on the Senate floor.

I’m a strong supporter of political parties and a strong believer in partial public funding of campaigns. Yet I find it very difficult to oppose Coburn’s proposal. I'd like to put the money into partial public funding for House races, but barring that, I think he's mostly right.

The original 1970s campaign finance regime had three separate sources of funds, for three separate phases of the process. There were matching funds for the primaries, which amounted to partial public financing of the nomination process. There was full public financing of the general election. Both of those were conditional: Campaigns taking the money were limited in overall spending for the nomination side, and they could raise and spend nothing else if they took the money for the general election.

Over time, the general-election system proved to have a major loophole, since party or outside-group spending was still allowed. That was fine with me, because it again established partial public financing. Floors are good policy; they help ensure that we’ll get a real campaign, with both major parties able to make their case to the American people.

But it’s become so easy to raise campaign money that no one takes the public funding anymore.

What of the third phase, the conventions? The problem is that, at about the same time that the modern system was set up, the conventions ceased to be decision-making bodies and were converted into, well, advertising for the presidential ticket.

I’m not sure that it makes sense for the federal government to subsidize the party structure, as opposed to subsidizing candidates. But it’s a lot harder to argue that it makes sense for the government to pay for this particular part of the candidates’ campaigns. About all I can come up with is that it’s a back-door way to preserve a bit of partial public financing, which I think is a stretch; or that there’s some compelling federal interest in preserving the form (if not the original function) of the conventions. I’m not sure the conventions would survive without the subsidy, but as much as I personally love the traditions, I pretty much think that if the parties and campaigns aren’t willing to pony up for them, there’s no reason to bother.

So should the money be eliminated? I wouldn’t quite follow Coburn’s path. What I’d do, instead, is tie it to general-election money. After all, in practical terms, the conventions are part of the general-election campaign. Simply make the party front the money, and then if its nominee chooses to accept public financing — and the constraints that come with it — then the party also get reimbursed for their convention. Otherwise, nope.

If I really had my druthers, I’d go ahead and trade in the entire, outdated presidential public finance system, and use the money to give each major-party nominee for the U.S. House something like $250,000 in public financing. Obviously that’s not what Tom Coburn wants — and it’s not something that’s likely to be of interest to current members of the House, since one of the main effects would be to make them work harder for reelection. But it would achieve something that’s valuable: making sure that everyone gets at least a minimally competitive election for the House.

What, exactly, is the subsidy for the party conventions getting us?