In an April 11 post, The New York Times' political blog, The Caucus, reported that Sen. John McCain's “campaign believes Mr. [Barack] Obama reneged on his pledge to accept public financing,” and stated: “The McCain campaign today circulated an editorial in The Wall Street Journal that questioned Mr. Obama's commitment to the public financing system.” However, the post did not report that McCain may have violated campaign finance laws by surpassing spending limits under the public financing system for the primary period. FEC chairman David Mason has taken the position that McCain cannot unilaterally opt out of public financing in the primary without FEC approval, meaning that every day that McCain spends beyond the limits of the public financing system, he could be breaking federal law.

The Associated Press reported on February 21: “The government's top campaign finance regulator says John McCain can't drop out of the primary election's public financing system until he answers questions about a loan he obtained to kickstart his once faltering presidential campaign. Federal Election Commission Chairman David Mason, in a letter to McCain this week, said the all-but-certain Republican nominee needs to assure the commission that he did not use the promise of public money to help secure a $4 million line of credit he obtained in November." The loan could have required McCain to remain in the race, regardless of whether his candidacy was viable, in order to receive matching funds to pay back the loan. A March 23 Washington Post article reported that “McCain has officially broken the limits imposed by the presidential public financing system,” and a February 22 article in the Post noted that "[k]nowingly violating the spending limit is a criminal offense that could put McCain at risk of stiff fines and up to five years in prison." Under the Presidential Primary Matching Payment Account Act, violators could face fines up to $25,000 and up to five years of jail time.

From the April 11 post on The Caucus, by reporter Jeff Zeleny:

Three days after telling contributors at a Washington fundraiser that he believed his campaign has created “a parallel public financing system,” Mr. Obama said today that he “wasn't trying to send a signal” about whether he intended to opt-out of the public financing system if he wins the Democratic nomination.

He said he would made a decision after his primary fight with Senator Hillary Rodham Clinton ends.

“What I was trying to suggest was that through the Internet and the enthusiasm of this campaign, we've created a model for being able to compete at the highest levels of politics without being dependent on big-moneyed interests,” Mr. Obama said. “And I think that's a real positive.”

Then, he added: “I would like to see a system preserved. And I intend, if I am the nominee, to have conversations with Senator McCain about how to move forward in a way that doesn't allow third parties to overwhelm the system.”

By the time the party's nomination is decided, of course, several third-party groups will be fully engaged in the presidential campaign. (They already are gearing up.)

So it remains an open question how productive any discussions could be, considering the McCain campaign believes Mr. Obama reneged on his pledge to accept public financing. The McCain campaign today circulated an editorial in The Wall Street Journal that questioned Mr. Obama's commitment to the public financing system.

Stay tuned.

Update, noon: A spokesman for Mr. McCain said that Mr. Obama seemed to be “hedging” or resorting to “clever language” as he sought to step away from a pledge he made last year to use public financing in a general election campaign.

“We will always welcome an open discussion with Barack Obama, but he has clearly committed to public financing in the general election should he win his Party's nomination, and we expect him to keep his word,” said Tucker Bounds, a spokesman for Mr. McCain.