Voters are bracing for the longest and most expensive presidential race in American history. The 2008 campaign will last two years and top $1 billion, and most candidates plan to cover the rising costs by ditching public financing so they can sidestep spending limits. For the first time since Watergate, private donors will likely supplant public funding for the entire election. That means America’s most expensive campaign may also be its least accountable, with a small group of multimillionaires exerting huge influence over which candidates are allowed near the White House. Think Jack Abramoff on steroids.

“It’s money, and only money, that is the reason we’re leaving today,” said Tom Vilsack, when he announced last month that he was the first candidate to drop out of a presidential race that had barely begun. As a two-term governor from the pivotal state of Iowa, Vilsack might have been a viable candidate, but he could not raise the money required for today’s campaign. Vilsack’s fundraising was dwarfed by early frontrunners such as Barack Obama and Hillary Clinton. Clinton has announced she will forego public financing for the primary and general election so she can raise unlimited cash.

To save the public financing system, Senator Russ Feingold has introduced legislation to raise spending caps, provide public financing six months earlier in the race and quadruple the matching funds for participating candidates. “The American people do not want to see a return to the pre-Watergate days of unlimited spending on presidential elections and candidates entirely beholden to private donors,” Feingold said when he introduced the Presidential Funding Act of 2007.

Fred Wertheimer, president of Democracy 21, a group that fights big money in politics, argues that without reform, campaigns are headed for an “extraordinary unlimited spending arms race” that will allow influence-peddling that the country has not “seen since the Watergate scandals.” Democracy 21 is endorsing Feingold’s bill and asking all the presidential candidates to support it. The only candidate who has signed on so far is Senator Barack Obama, who has also promised to voluntarily follow the spending caps if the Republican nominee will do the same. Senator John McCain just made a similar pledge.

Common Cause, a nonpartisan government accountability organization, also is backing Feingold’s bill. “People elected to office in our country from President to state legislator should not be beholden to the donors,” Common Cause spokesperson Mary Boyle told The Nation. She also said their 300,000 members will press presidential candidates to support public financing for all federal elections.

Of course, there is no way to know whether the new Congress will act on Feingold’s bill. Skeptics note that most campaign finance proposals face an uphill battle in Congress because incumbents want to protect the system that put them in power. Conservative opponents argue that reforms are futile because money always finds a way into the process. Bradley A. Smith, the former Republican Chairman of the Federal Election Commission, once wrote that campaign finance reform simply “never works.”

Yet the cynicism about the merits and prospects of campaign finance reform ignores history. In 2002 the Republican Congress summoned the will to act when Feingold and McCain led a large bipartisan majority to ban the huge “soft money” donations in 2002. Surely the new Democratic Congress, which ran against a “culture of corruption,” can at least match the Republicans’ legislative record on campaign finance reform.

On the merits, the public funding instituted after Watergate worked very well. From its inception in 1976 until the 2000 election–when George W. Bush became the first candidate to opt out–challengers beat incumbents in three out of the five races when incumbent Presidents ran for re-election. Overall during that period, Democrats were elected three times and Republicans four times. Public funding drastically reduced how much money candidates had to raise, while insuring financial parity between the two candidates in the general election. Republicans criticized the system and some called for its abolition, but the fact remains that both parties used the funds and played by the rules for a quarter-century. The model worked, it just wasn’t built for length and cost of contemporary campaigns. For example, the 2000 race was twice as expensive as 1976, even after adjusting for inflation, and almost twice as long. The first 2008 candidates announced two years in advance; Bill Clinton did not announce his first presidential bid until thirteen months before Election Day.

In fact, the major downside to Feingold’s plan is that it would reinforce today’s longer campaigns by distributing funds six months earlier than the old rules. His staff says the proposal simply fits the reality of a longer calendar. But a more ambitious plan would require states to delay their primaries, cutting the cost of the race and giving Americans a reprieve from the two-year campaign. That would be a popular approach, since the public wants shorter campaigns and less politics. Either way, Feingold’s plan is a critical first step to preventing presidential campaigns from sliding back to the unlimited spending and corruption of the Watergate era.