Barack Obama’s stunning fundraising total for September leaves little doubt that the public financing system he eschewed is now in serious peril. Obama’s campaign raised $150 million last month alone — dwarfing the nearly $85 million limit John McCain agreed to for the entire general election campaign cycle when he accepted public funds.

The disparity may now make the public financing system look anachronistic, but reformers thought the system was a major step forward when it was created more than three decades ago. In 1974, Congress enacted the framework of the system we have today: optional matching funds for primary candidates who meet certain qualifications and agree to certain limits, as well as an optional grant for major party nominees (and “minor” party candidates who garner between 5 percent and 25 percent of the presidential popular vote) who agree to limit their general election spending to only that grant amount. The initiative came in the aftermath of the Watergate scandal, when campaign finance reformers backed a system of presidential public financing to reduce the influence of well-heeled special interests on the presidential election process. The funding comes from a check-off box on annual IRS return forms that allows taxpayers to designate up to $3 (originally $1) to go into the public funding pot.

From 1976 to 1996, most serious White House hopefuls accepted both the primary matching funds and the general election grant. Though George W. Bush (in 2000 and 2004) and John Kerry (in 2004) became the first of their parties’ nominees to opt out of the matching funds for the primary period, both accepted the general election public grant.

The grants were initially set at a maximum of $10 million for a primary season match and $20 million for the general election, but they were indexed for inflation. So the 2008 candidates could each get up to $42.05 million for the primaries and $84.1 million in the general. But in an age where candidates can raise $6 million in a day — and independent expenditure groups spend hundreds of millions on attack ads — many feel the system has failed to keep pace with the cost of modern elections.

In 2004, after agreeing to limit his general election spending to only the $74.62 million public grant, John Kerry found himself financially hamstrung and unable to respond to a blitz of critical ads against him by the Swift Boat Veterans For Truth, a 527 committee. Kerry told the Center in 2007 that unless the system is fixed to adequately fund a modern campaign, the system would die. “If you are not going to reform it, it’s going to be scrapped by the candidates who will choose not to do it.”

This election has proven Kerry right. Despite initially pledging to participate in the primary matching funds system, John McCain backed out and opted to forgo the federal funding, thus freeing himself from the voluntary primary spending cap. Barack Obama originally vowed to take the general election public grant if McCain did the same, but opted to forgo the federal financing and free himself from the voluntary general election spending limit — the first major-party nominee to do so since the system’s inception. Both criticized the other for these moves. Both ultimately raised significantly more in contributions than they would have received by staying in the system. And for that reason, without a major adjustment of the system, we can expect 2012 contenders to opt out of the public financing system faster than you can say “I’m a candidate with way too much money, and I approve this message.”