In a take-no-prisoners column Friday, Paul Krugman pretty much levels the Republican presidential field. They are, in a word, grifters, Krugman writes, representatives of a party that has defined respectability down. And the gullible base is only too happy to buy the snake oil they are selling.

Perhaps the most obvious example was Ben Carson's denial Wednesday night that he is involved with the company Mannatech, a purveyor of nutritional supplements that has been forced to pony up $7 million in a deceptive practices lawsuit. Carson simply and brazenly lied, denying his involvement, and the audience applauded him and booed the questioners. "These days," Krugman writes ruefully, "in his party, being an obvious grifter isn’t a liability, and may even be an asset." And this doesn't just go for the outsider candidates like Trump and Carson, who are still in the lead. Krugman proceeds to lay out the taxonomy of the grift:

Start with the lowest level, in which marketers use political affinity to sell get-rich-quick schemes, miracle cures, and suchlike. That’s the Carson phenomenon, and it’s just the latest example of a long tradition. As the historian Rick Perlstein documents, a “strategic alliance of snake-oil vendors and conservative true believers” goes back half a century. Direct-mail marketing using addresses culled from political campaigns has given way to email, but the game remains the same. At a somewhat higher level are marketing campaigns more or less tied to what purports to be policy analysis. Right-wing warnings of imminent hyperinflation, coupled with demands that we return to the gold standard, were fanned by media figures like Glenn Beck, who used his show to promote Goldline, a firm selling gold coins and bars at, um, inflated prices. Sure enough, Mr. Beck has been a vocal backer of Ted Cruz, who has made a return to gold one of his signature policy positions. Oh, and former Congressman Ron Paul, who has spent decades warning of runaway inflation and is undaunted by its failure to materialize, is very much in the business ofselling books and videos showing how you, too, can protect yourself from the coming financial disaster. At a higher level still are operations that are in principle engaging in political activity, but mainly seem to be generating income for their organizers. Last week The Times published an investigative report on some political action committees raising money in the name of anti-establishment conservative causes. The report found that the bulk of the money these PACs raise ends up going to cover administrative costs and consultants’ fees, very little to their ostensible purpose. For example, only 14 percent of what the Tea Party Leadership Fund spends is “candidate focused.”