(CNN) -- When is the most recent time a decision by a presidential candidate ended up being good for him and his opponent?
Roland S. Martin says Sen. Barack Obama's decision to opt out of public financing is a boon for both campaigns.
But that is certainly the case with Sen. Barack Obama's decision last week to become the first candidate since public financing went into effect in 1976 to make the bold move to opt out of it.
It's a huge help to Sen. John McCain because the GOP candidate has cast himself as the fierce independent who is all about reform, even to the point of opposing President Bush on key initiatives.
By ceding ground on this issue, Obama goes against all the signals he sent for months on the issue of public financing of campaigns.
Obama made the decision in a video message to his supporters, and it didn't take long for the McCain campaign to jump all over the Democrat, decrying the move as the clearest indication that the junior senator from Illinois is not the breath of fresh air that he has portrayed himself to be.
"Today, Barack Obama has revealed himself to be just another typical politician who will do and say whatever is most expedient for Barack Obama," McCain communications director Jill Hazelbaker said in a statement.
"The true test of a candidate for president is whether he will stand on principle and keep his word to the American people. Barack Obama has failed that test today, and his reversal of his promise to participate in the public finance system undermines his call for a new type of politics."
Don't be surprised to see McCain make this decision a significant part of his campaign, and he and his surrogates will hammer Obama repeatedly on the one issue that the senior senator from Arizona has made his calling card.
How does this help Obama? Easy: He likely will blow McCain away when it comes to fundraising, giving him a huge advantage in the fall election.
Obama would have been nuts to accept public financing because he would have been able to spend only $85 million. He already has raised nearly $275 million, and he will have the resources to dwarf McCain. No one thought he would be able to raise such vast sums of money, but with 1.5 million donors contributing to his campaign, he has amassed a formidable operation.
Had Obama stuck to his guns and accepted public financing, McCain's team would have lauded him publicly but laughed him off as a naive fool for doing so. And his fellow Democrats would have berated him to no end for taking away a victory in the one area they have lagged behind Republicans for years: fundraising.
This is a cat-and-mouse game, similar to McCain's decision to back offshore oil drilling in the United States despite years of opposition. He knows the move could backfire against him by making him appear to be a flip-flopper, but McCain hopes voters will put their concerns over $4-a-gallon gas over the long-term opposition to the drilling.
Obama's risky move could tarnish the image he has burnished of being a different kind of politician. Hard-core Democrats will welcome the decision, but independents might have a problem with it.
He's hoping voters will accept his position that the Republican attack machine will blast him with unregulated funds. Obama also hopes that voters will take to his decision not to take funds from Washington lobbyists or political action committees.
Running for president is about taking risks. We'll soon see who was right in this area.
Roland S. Martin is an award-winning journalist and CNN contributor. He is the author of "Listening to the Spirit Within: 50 Perspectives on Faith." Please visit his Web site at http://www.rolandsmartin.com/.
The opinions expressed in this commentary are solely those of the writer.