At one point during Wednesday’s Republican debate, Ben Carson was asked about his involvement with Mannatech, a nutritional supplements company that makes outlandish claims about its products and has been forced to pay $7 million to settle a deceptive-practices lawsuit. The audience booed, and Mr. Carson denied being involved with the company. Both reactions tell you a lot about the driving forces behind modern American politics.As it happens, Mr. Carson lied. He has indeed been deeply involved with Mannatech, and has done a lot to help promote its merchandise. PolitiFact quickly rated his claim false, without qualification. But the Republican base doesn’t want to hear about it, and the candidate apparently believes, probably correctly, that he can simply brazen it out. These days, in his party, being an obvious grifter isn’t a liability, and may even be an asset.