Deep within Brad Smith’s must read post on the McCain Public Financing mess is this point I had not thought of before:

This week, the truncated FEC’s Chairman, David Mason, sent the McCain campaign a letter. Mason noted that the FEC would treat McCain’s notification that he was “withdrawing” from the matching funds subsidy program as a request to have the Commission withdraw its previous authorizations of funding for McCain, in accordance with the afore-quoted 2 U.S.C. 437c(c). Mason also asked for verification that Senator McCain had not pledged his authorization as collateral. Sources say that McCain’s campaign lawyer, former FEC Commissioner Trevor Potter– who has long lobbied for “strict” enforcement of the law and who presumably is the architect of McCain’s campaign finance strategy– exploded at FEC staff. If true, it once again indicates the inability of McCainiacs to understand who has their best interest at heart. Mason’s letter is carbon copied to Judith Tillman, the Treasury official who oversees payments from the matching funds account. What does this mean? I can’t be sure, but I suspect it means that Treasury was about to send McCain a check that the latter didn’t want. Note that once the FEC certifies a candidate for matching funds, the Treasury — meaning Ms. Tillman’s division of Treasury — is legally obligated to cut the check. It has no power to withhold the money. And who can tell it to withhold the check? Not John McCain (though he can refuse to cash it), but only the power that authorized it, in this case the FEC. And under 437c(c), the FEC appears to need four votes to do that — a point Chairman Mason made to Senator McCain. Sending the letter to McCain may be enough for Commissioner Tillman at Treasury to hold off on sending McCain money while waiting for the situation to straighten out. Chairman Mason may have been saving the McCain campaign’s bacon, even if the latter is too arrogant and stupid to know it.

Might this explain why (Democratic) Commissioner Weintraub did not sign the letter as well? UPDATE: The answer is no. I have heard from many readers that it is routine for the Chairman, and only the Chairman, to sign letters from the Commission.