The Republican Party is running a three-level campaign this year that gives its candidates a wealth of advantages—in flexibility, deniability, and determination.

At the first level are the party's candidates, who can be as reasonable or as angry, as moderate or as conservative, as their circumstances require.

Next come the outside groups that refuse to disclose their donor lists. They are doing the dirty work of pounding their Democratic opponents in commercials for which no one is accountable. The Republican candidates can shrug an innocent "Who, me?" Deniability is a wonderful thing.

And then on the far right, Glenn Beck and his allies cast President Barack Obama as the central figure in a conspiracy against America itself, fueling participation by the most extreme 10 percent or 15 percent of the electorate.

Their crackpot ideas, as the historian Sean Wilentz documented in the New Yorker recently, originated in the 1950s and '60s, in the paranoid theorizing of the John Birch Society. But whereas responsible conservatives such as William F. Buckley Jr. denounced the Birchers and the rest of the lunatic fringe back then, Republicans this time are riding the radical wave. In some cases (Sharron Angle in Nevada), the extremists are their standard-bearers.

It's quite brilliant in its way, and, judging by the polls, it's working out rather nicely for the Republicans. They are also profiting from the discontent bred by an economic downturn that began on their watch.

It's strange to observe this process in New Hampshire, a state whose voters are famously engaged and generally moderate. They are also partially immunized against the power of television advertising, accustomed from their presidential primary to television screens filled with political messages of all kinds.

Kelly Ayotte is all charm and reasonableness as she works her way through the luncheon crowd at a meeting of New England's largest Rotary Club at the Red Hook Brewery here last week.

In her brief address to the assembled business people and professionals, Ayotte, the former state attorney general and Republican nominee for the U.S. Senate, offers the usual Republican criticisms of a Washington that "has been spending too much money" and "not focusing on getting our economy back on track." She commits to "lower taxes on small business and less regulation" but also pledges not to be a partisan figure. "Often, I'll be bucking my own party," she promises.

Frank Guinta, the Republican House nominee, was also the soul of equanimity when it was his turn to speak. He, too, stands four-square against mindless partisanship while sticking to his party's message on taxes, spending, and jobs.

Rep. Paul Hodes, Ayotte's Democratic opponent, could not attend the event, but Rep. Carol Shea-Porter, the incumbent Democrat whom Guinta hopes to defeat, minces no words in bravely defending tax increases on upper-bracket earners before a crowd that, judging from its questions, includes a great many of them.

"We all have a responsibility to do what we can to get out of this debt," she says. And she stoutly defends her vote for health-care reform, asking the crowd if it really wants to repeal the new law's consumer protections or its tax credit to help small businesses buy insurance.

You would never know that, away from the friendly Rotarian civic moment worthy of Tocqueville, Hodes was being pounded on the air by one of this year's big outside conservative spenders, American Crossroads. "The guy just can't tell the truth," one ad declares, citing the state's leading conservative newspaper. For her part, Shea-Porter has been hit by the pious-sounding Revere America group for her support of Obamacare. The ad warns ominously, and with no basis: "Your right to keep your own doctor may be taken away."

Hodes estimates that he has been battered by $4 million in outside ads, and, in an interview, condemns "the idea that corporations and third-party interests can flood our airwaves with millions of dollars without our knowing who they are." But he gamely predicts that sophisticated New Hampshire voters are "less susceptible to the garbage being thrown at them."

What's striking is that both Hodes and Shea-Porter are unafraid to embrace their votes for Obama's program, which makes you wonder if their party and the administration would be in better shape now if both had long ago embarked on a systematic defense of their actual record.

As it is, these Democrats and scores like them elsewhere face Republican opponents who can be calmly affable, knowing they have behind them oodles of secret cash and a far right that sees November 2 as Armageddon. 

(c) 2010, Washington Post Writers Group

Related: Bitter Brew, by the Editors; Extreme Makeover, E. J. Dionne Jr.