June 22 (Bloomberg) -- Democratic Senator Barack Obama's decision not to accept public funds for his presidential campaign puts the financing system at risk, said Senator Joe Biden, an Obama supporter.

``In terms of undermining the public financing idea for everyone'' the decision ``doesn't help,'' Biden, a Delaware Democrat, said today on NBC's ``Meet the Press'' program. ``It's going to be harder to make the case'' for public financing, he said.

Still, Biden said Obama has kept his commitment of ``reducing the influence of big money in his campaign, unlike other campaigns.'' Almost 80 percent of Obama's contributions are $100 or less, ``so he's keeping with the purpose of public financing,'' Biden said.

Obama announced his move on June 19, calling the taxpayer- funded structure for the general election ``broken.'' Previously, he had promised to seek an agreement with the Republican nominee to take public money and the accompanying spending limits. Doing so would have meant abandoning record amounts of donations and surrendering an advantage over Republican candidate John McCain.

Senator Lindsey Graham, a McCain supporter appearing on the same program with Biden, said Obama ``is reinforcing everything that's wrong with politics.''

``This is a game changer in terms of the general election,'' said Graham, of South Carolina. ``This will not go unnoticed by the American people.'' McCain plans to take public financing for the general election campaign.

New Mexico Governor Bill Richardson defended Obama on the CBS News program ``Face the Nation,'' saying the Illinois senator's decision ``is in the spirit of reform of the public financing system.''

Through May 31, Obama has taken in $277 million, $10 million of that for the general election. McCain raised around $121 million. The taxpayer funding available for the general election is $84.1 million for each candidate.

To contact the reporters on this story: John Brinsley in Washington at jbrinsley@bloomberg.net; Jeff Bliss in Washington at jbliss@bloomberg.net

Last Updated: June 22, 2008 14:12 EDT