On one subject the three leading presidential candidates agree: that publicly financed presidential campaigns are a good thing.

Barack Obama even put it in writing: In a survey last year, he said that if nominated, he would "aggressively pursue an agreement with the Republican nominee to preserve a publicly financed general election." John McCain made a similar pledge. Hillary Clinton, although unwilling to commit, hasn't ruled it out.

The two parties' eventual nominees should agree to sharply limit — or better yet, eliminate — private funding in the general election campaign.

Public financing can be effective in limiting the influence of special interests and the money they use to buy access to the candidates. And while each candidate could spend no more than $85 million — a far cry from the $300 million it's anticipated they'll spend — surely it's enough to serve the public interest.

Unfortunately, naked ambition may quash reform.

Obama, who raised $32 million in January alone, has refused to recommit for now, citing the complexities of the issue, including fundraising and spending by outside groups. McCain, seeing a chance to wound his anticipated rival, accused Obama of "Washington double-speak."

But McCain is hardly being high-minded. It's to his advantage to hold Obama's and Clinton's spending down; each of them has raised more than twice as much as he has. And having virtually secured the GOP nomination, he's rejected public funding for the primaries now that private donations are rolling in. Now he can target the Democrats with as much cash as he can raise.

It's clear the public financing system, created in the 1970s after the Watergate scandal, is badly outdated; the financial caps can't compete with the costs of the current campaigns, especially with the longer primary season. New legislation in Congress aims to fix that, but not until 2012.

For now, Obama, Clinton and McCain should to put their millions where their mouths are. They should participate in public financing, and support the integrity of the election process.