WASHINGTON — Are we spending our democracy into oblivion?

This is the time of year when media scribblers bemoan how nasty political campaigns have become. The complainers are accused of a dainty form of historical ignorance by defenders of mud-slinging who drag out Finley Peter Dunne’s 1895 assertion that “politics ain’t beanbag.” Politics has always been nasty, the argument goes, so we should get over it.

In fact, structural changes in our politics are making campaigns more mean and personal than ever. Even Dunne might be surprised. Outside groups empowered by the Supreme Court’s Citizens United decision are using mass media in ways that turn Americans off to democracy, aggravate divisions between the political parties, and heighten animosities among citizens of differing views.

Studies of this year’s political advertising show that outside groups are blanketing the airwaves with messages far more negative than those purveyed by the candidates themselves. That shouldn’t surprise us in the least. “Candidates can be held accountable for their ads,” says Robert Weissman, president of Public Citizen, a consumer organization that is trying to encourage candidates to disown dark money. “The outside groups are unknown, and have confusing names.”

No one is advertising under the moniker “Influence Peddlers for Crummy Politics.”

There is far too much complacency about big money’s role in this year’s campaigns, on the grounds that both sides have plenty of it. This misses the point. “It doesn’t balance it out if you have billionaire Republicans battling billionaire Democrats,” says Weissman. “You still have billionaires setting the agenda for the election.”

Moreover, a focus just on this year’s competitive Senate and House races misses the enormous impact a handful of very wealthy people can have on state and local campaigns. A new report by the Brennan Center for Justice details how, at a relatively modest cost to themselves, a privileged few can change how government that is supposed to be nearest to the people is actually carried out.

“At this scale, you don’t have to be a Koch brother to be a kingmaker,” the report informs us. Worse, the supposedly “independent” spending of the super-rich kingmakers isn’t independent at all. The report documents how closely the activities of supposedly outside groups are coordinated with insiders and the candidates themselves.

Like everything else in our politics these days, Citizens United is usually debated along ideological lines. Progressives typically hate it. Conservatives usually defend it. But citizens of every persuasion should be worried about what this precedent-shattering decision has unleashed. More than ever, politics is the only profession that regularly advertises against itself. If voters feel cynical, the outside groups — on both sides — are doing all they can to encourage their disenchantment.

A study by the Wesleyan Media Project of ads aired between Aug. 29 and Sept. 11 found that 55 percent of them in U.S. Senate elections were negative, up from 43.7 percent over the same period in 2010. Wesleyan found that 91.4 percent of the ads run by outside groups in support of Democrats were negative, compared with 41.9 percent of those run by Democratic candidates themselves. For Republicans, 77.9 percent of the group ads were negative, compared with only 12.3 percent of the candidate ads. Negative ads were down slightly in the next two-week period, but there were still more negative commercials run this year than in the comparable period in 2010.

Defenders of massive spending on advertising, positive or negative, will make the case that at least the ads engage voters. Not necessarily, and certainly not this year. Indeed, the Pew Research Center found in early October that only 15 percent of Americans are following the elections “very closely.” Interest in the campaign, says Scott Keeter, director of survey research at Pew, “is the lowest it has been at this point in an off-year election in at least two decades.”

Hardly a day goes by without someone lamenting how polarized our politics has become. Can anyone seriously contend that the current way of running and financing elections is disconnected from the difficulty politicians have in working together? “How are they supposed to get along with the other side the day after the election?” Weissman asks. Writing recently in Foreign Affairs, the sometimes dissident conservative writer David Frum argues that “the radicalization of the party’s donor base has led Republicans in Congress to try tactics they would never have dared use before.”

Thus the tragic irony: Citizens United is deepening our divisions and turning more citizens into bystanders. Our republic can do better.

E.J. Dionne’s email address is ejdionne@washpost.com. Twitter: @EJDionne.

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