If anyone had doubts about the madness that has spread through a large part of the American political spectrum, the reaction to Friday’s better-than expected report from the Bureau of Labor Statistics should have settled the issue. For the immediate response of many on the right — and we’re not just talking fringe figures — was to cry conspiracy.

Leading the charge of what were quickly dubbed the “B.L.S. truthers” was none other than Jack Welch, the former chairman of General Electric, who posted an assertion on Twitter that the books had been cooked to help President Obama’s re-election campaign. His claim was quickly picked up by right-wing pundits and media personalities.

It was nonsense, of course. Job numbers are prepared by professional civil servants, at an agency that currently has no political appointees. But then maybe Mr. Welch — under whose leadership G.E. reported remarkably smooth earnings growth, with none of the short-term fluctuations you might have expected (fluctuations that reappeared under his successor) — doesn’t know how hard it would be to cook the jobs data.

Furthermore, the methods the bureau uses are public — and anyone familiar with the data understands that they are “noisy,” that especially good (or bad) months will be reported now and then as a simple consequence of statistical randomness. And that in turn means that you shouldn’t put much weight on any one month’s report.