This may not be the dirtiest presidential election ever, but the level of political discourse isn't what makes the current campaign different. Rather, it's how that discourse is, or isn't, paid for.

Although charges that Bill and Hillary Clinton were murderous drug runners might have set a new standard for vicious dishonesty, not to mention hilarity, historians of American politics prefer to look further back. Most agree that the benchmark for dirt was established by the John Quincy Adams and Andrew Jackson campaigns of 1824 and 1828.

No one, for example, has taken advantage of President Bush's reported friendship with Vladimir Putin to accuse him of being a pimp for the Russian president. But in 1824, Jackson's supporters charged Adams with having been a pimp for the tsar when he was the U.S. ambassador in Moscow. Adams's supporters did get the jump on 1990s Republicans by accusing Jackson of murder. The difference was that Jackson actually had killed several men in duels, and the accusations of murder stemmed from claims he had not followed the rules of dueling. Less sensational claims, such as tax evasion, adultery, bribery, and fraudulent practices in private business, pop up fairly regularly decade after decade.

The level of political discourse might not have changed, but the way we pay for it has. Imagine that the year is not 2004 but 1904, and imagine that television had already been invented. When Sinclair Broadcasting announced it would air a film attacking Senator Kerry just before the election, Democrats would not have appealed to federal regulatory agencies or gone after Sinclair's advertisers. They would have used their own stations to launch a counterattack.

The media of those days were openly partisan, a tradition that went back to the days when Hamilton and Jefferson and their supporters used government as well as private money to set up rival newspapers. In 1904, New Yorkers who walked to work with the Tribune or the Sun under their arms identified themselves as Republicans, just as those who read the Times or the World announced that they were Democrats.

By mid-century that partisan character had changed, as journalists began to see themselves as independent professionals. The mass media still carried strongly partisan messages, but no longer as voluntary efforts by editors and reporters to help their party win elections. The media were now middlemen, selling air time to the parties. By the latter part of the twentieth century, most Americans saw an overtly partisan media as something we had outgrown.

At the beginning of the twnety-first century, though, part of the mass media have returned to the earlier model. Fox News, Sinclair Broadcasting, most of the cable TV shouting heads, and nearly all of talk radio are as partisan as the newspapers of 1904. What that means is that Democrats are operating only in the paid media model of the last 50 years, while Republicans also get to take advantage of the free media model of 100 years ago.

The political impact of the Swift Boat attacks wasn't the result of millions of dollars spent to buy air time but of millions of dollars worth of free publicity from conservative media. Having few outlets of their own, Democrats relied on fact checking by journalists. When that predictably had far less impact than the conservative attack, liberals denounced journalists as no more than stenographers, who treated even discredited assertions merely as part of a he said/she said exchange.

The charge is on target, but it also reflects some wishful thinking. Reporters operate in an environment where Republicans have a louder voice and more political power than Democrats. It's simply not realistic for Democrats and liberals to expect formally neutral journalists to do their fighting for them.

In the last 100 years, we've tried two different ways of paying for campaign speech, in two different models for a national media. Looking back, it's clear that it's not important whether we pay for political discourse directly through partisan media or indirectly through paid spots in nonpartisan media. Our democracy has thrived under both models. But it's also clear that we can't expect partisan balance in either media model if the parties themselves aren't evenly balanced.

When one party is much stronger than the other, reporters' willingness to take dictation from both sides may be as much as the weaker party can ask for. Of course, it helps if the weaker party can think of something to say. One reason why the major media channeled administration propaganda in the run up to the war on Iraq is that all but a tiny handful of Democrats -- maybe because they were hazy about their own position, or were just too scared of Republican hit men -- kept their mouths shut. A healthy democracy needs at least two parties. If one party allows itself to fall silent, it can't expect journalists to pick up the slack.