Recently, Obama has been testing arguments against the public-financing system. He trotted out another one today:

"We know that the check-off system has been declining in participation, and as a consequence, the amount of money raised through the public financing system may be substantially lower than the amount of money that can be raised through small donations over the Internet, which presents candidates, then, with some pretty tough decisions in terms of how they want to move forward if they want to compete in as many states as possible."

Obama also responded to the role of large bundlers in his campaign (as opposed to the small Internet donations his campaign heralds as a "parallel public financing system"):

"They are very active, though they don't interact much with me," he said. "They interact mostly with each other. They are not as a general rule part of my day-to-day policy or advisory committee, although there are some people who have raised money for me who are also prominent business leaders. And so, for example, if we were putting forward a economic plan, and there was some expertise there, we might tap into it. But they're not as a general rule part of our policy making apparatus, or determining the course of the campaign. Their focus is on raising money.”

Finally, on that fact that he didn't check the $3 donation box to the public financing system on his tax returns:

"You know, I have always checked off $3 in the past, so I'm going to have to talk to my accountant," he said. "That may have been an oversight or a mistake. In all my previous years, I have, so I should find out what's going on there. This may be a situation where my accountant, through oversight, didn't do it."