Now she is favored in the year’s most high-profile Senate race. Unless Mr. Reid can muster a huge turnout, there is a strong chance that Ms. Angle will become a United States senator, and she will have done so largely by exploiting fears of illegal Hispanic immigrants in an economically nervous state. One of her television ads, which calls Harry Reid “the best friend illegals have ever had,” shows dark-skinned characters sneaking along a border fence, juxtaposed with a Mexican flag.

In a particularly preposterous bit of spin, she told a group of Hispanic students a few days ago, when she did not realize she was being recorded, that those people were not necessarily Hispanic. They might have been coming through the Canadian border, she said, calling it “the most porous border that we have” and adding that that is “where the terrorists came through.” (The Canadian ambassador immediately protested this nonsense.) For a candidate who famously told Mr. Reid to “man up” at the debate, she should at least take responsibility for her own sneering innuendo.

She is, however, willing to persist in her illusion that Social Security can be fixed only by turning it over to private accounts, a toxic position with older voters that many of her fellow Tea Party candidates pretend they haven’t considered. And she has gone much further than even Christine O’Donnell, the Republican candidate for United States Senate in Delaware, in repudiating the need for separation of church and state. That doctrine, Ms. Angle has said, is “unconstitutional”; she prefers to give religion an expansive position in public life.

Mr. Reid, who is far more comfortable maneuvering compromises through the back rooms of the Senate than campaigning among actual voters, lost his best chance to skewer his opponent’s positions in the debate. Those voters who did not know about his efforts to save jobs in Nevada, or his proposals for using tax incentives to create even more, still don’t.

He might have laughed at her assertion that the nascent health care law is responsible for persistent joblessness, or demanded to know her alternative plan for covering the millions of uninsured. Instead of saying he would leave it to “the experts” to decide what to do about tax cuts for the wealthy, he should have clearly explained to voters how important it is to the nation’s long-term future to raise taxes on families making more than $250,000.