Billionaire investor Warren E. Buffett humorously described in The New York Times last Sunday one way to enact a small piece of campaign finance reform. As novel as his idea was, however, it missed a large part of the problem and illustrated why politicians have been able to keep their corrupt system for so long.

Mr. Buffett modestly proposed to eliminate soft money from campaigns by raising the individual contribution limit from its current $1,000. He suggested the new limit be $5,000, but that no other contributions, including from corporations, be allowed. To persuade Congress to go along with a reform bill that carried this restriction, he introduces the “eccentric billionaire,” or E.B.

“Just suppose some eccentric billionaire (not me, not me!),” he writes, “made the following offer: If the bill was defeated, this person – the E.B. – would donate $1 billion in an allowable manner (soft money makes all possible) to the political party that had delivered the most votes to getting it passed. Given this diabolical application of the game theory, the bill would sail through Congress and thus cost our E.B. nothing (establishing him as not so eccentric after all.);;

Mr. Buffett has proven himself a whiz at investments, but he may need to review the Senate leadership prospectus before betting on this bill. The heads of both parties in that club would do their best – and their powers are considerable – to make certain that E.B.’s bill died a quiet death without ever coming up for a vote.

“The beauty of this plan is that it would highlight the absurdity of claims that money doesn’t influence congressional votes,” Mr. Buffett writes. But it is there that his idea falls down. Americans don’t need to be persuaded that money corrupts the political system; they already believe it. What keeps the money rolling in is that the current system makes it extremely hard for voters to see the connection between campaign donations and specific votes. That is, collectively voters know the system is rigged, but individually they don’t know exactly how and whether or not it is rigged in their favor.

One rescuing idea behind Mr. Buffett’s plan is that, even if some E.B. did come along with this offer and found the bill permanently stuck in some subcommittee, he would be helping to set the price on this corruption, establishing that it is worth at least something more than a billion dollars to Congress. And that, too, wouldn’t cost him a penny.