The campaign finance reform law enacted after former President Richard Nixon’s 1972 re-election campaign and the Watergate scandal was straightforward. Presidential candidates who complied with limits on campaign contributions and expenditures would receive public matching funds for their primary campaigns. Each general-election presidential nominee of the two major parties would receive a lump-sum grant to run his campaign as long as he agreed to limit spending to the amount of the grant and not to accept any private contributions.

Its intention was to create “a level playing field” where an underfinanced underdog candidate could have a fighting chance against the front-runner with the deepest pockets and biggest financial backing. Because the reform law was on the books, an out-of-office former governor could challenge a sitting president in the primaries and come within a switch of only 54 delegate votes at the national convention of winning the nomination.

That was 1976, and the challenger to President Gerald Ford, of course, was Ronald Reagan, who under the Watergate reform law ran three presidential campaigns in which he abided by the contribution and spending limits, and twice as the winning Republican nominee ran campaigns financed entirely by taxpayer funds. (I have yet to hear any conservatives accuse the Gipper when he cashed those Treasury checks to finance his campaign of accepting “political food stamps.”)

George H.W. Bush ran twice for president and twice for vice president in campaigns that willingly accepted the law’s contribution and expenditure limits and public matching funds. Bill Clinton and Jimmy Carter in four presidential campaigns between them did the same. George W. Bush accepted public funds for his general election campaigns even after he had raised and spent only private money in the pre-convention period and not abided by the statutory primary spending limits.

Republicans, as the anti-regulation, pro-business party, have historically been more successful at raising campaign money than Democrats. In fact, in the first four national elections of this decade, the Republican Party outraised the Democratic Party, according to the respected Center for Responsive Politics, by a mere $678 million.

But then came 2008. The country was tired, after eight years of the Bush administration, of Republicans. The Democratic nominee was a young, cerebral, eloquent, appealing African-American with the golden touch when it came to raising money. Barack Obama became the first major-party presidential nominee since Nixon to finance his general election campaign exclusively by private money. Like Nixon in 1972, Obama in 2008 outraised his opponent by more than 2-to-1 — actually by $745 million to John McCain’s $368 million.

By rejecting the campaign finance law in 2008, Obama won a short-term political advantage while losing for himself and his party the moral high ground on the question of political money reform. Aided by U.S. Supreme Court decisions that for the first time in more than a century permit corporations to directly — as well as anonymously — bankroll commercials that attack or endorse a candidate, Republicans in 2010 enjoyed a 20-to-1 spending advantage over Democrats from outside groups not required to disclose their donors.

Now that they have proof of how well they can do in elections without contribution and spending limits, House Republicans almost unanimously voted this past week to end public funding of presidential campaigns. As an incumbent, President Barack Obama may well be able to privately raise $1 billion, but with no spending or contribution limits, in the long run Republicans — and seven-figure, secret donors — will have the upper hand in American politics.

The era — between Nixon and Obama — may be remembered as the Golden Era of Campaign Finance Reform.

Mark Shields is one of the most widely recognized political commentators in the United States. The former Washington Post editorial columnist appears regularly on CNN, on public television and on radio. Click here to contact him.