It's still crazy even if a bunch of people like it.

With Mitt Romney's selection of Paul Ryan as his Vice-Presidential candidate, there has been a great deal of discussion about Ryan's economic plan with many in the media suggesting that Ryan was a great choice because of his knowledge of economics (he has a BA) and the popularity among Republicans of his comprehensive budget plan introduced into Congress earlier this year. One such media figure is Joe Nocera who, in an op-ed in the New York Times today provides an excellent example of an Ad Populum. He writes:

Simply dismissing these ideas [Ryan's budget plan] as crazy is a mistake. There are many people in the country who agree with Ryan — as they showed two years ago, when they elected 87 Republican freshmen, many of them Tea Party-backed political novices, to the House of Representatives, who went to Washington vowing to shrink the federal government. Although they have had only marginal success so far, it hasn’t been for lack of trying. Their desperate urgency gave us, among other things, the debt-ceiling crisis, in which they risked putting the government in default.

Essentially, Nocera is arguing that we should take Ryan's plan seriously because many people agree with and like the plan. In fact, as many respectable economists have noted, Ryan's plan is junk combined with wishful thinking designed solely to make the rich even richer at the expense of everyone else. As Paul Krugman argues:

Look, Ryan hasn’t “crunched the numbers”; he has just scribbled some stuff down, without checking at all to see if it makes sense. He asserts that he can cut taxes without net loss of revenue by closing unspecified loopholes; he asserts that he can cut discretionary spending to levels not seen since Calvin Coolidge, without saying how; he asserts that he can convert Medicare to a voucher system, with much lower spending than now projected, without even a hint of how this is supposed to work. This is just a fantasy, not a serious policy proposal.

For Nocera to argue that we should take the plan seriously because many people like it is an excellent example of an ad populum. Given the complexities of economics and the lies and distortions people like Ryan are willing to spew, the fact that many people like Ryan's plan is only evidence of the wrongness of many people, and provides no justification for taking Ryan's budget proposals seriously.

h/t to Tristero