Democratic U.S. presidential candidate Senator Bernie Sanders. (REUTERS/Jay Paul)

It's a little bit unclear what Bernie Sanders has against the deodorant aisle. It is apparently, in the eyes of the Vermont senator seeking the Democratic nomination for president, a proxy for the ills of the American economy. Too many deodorant choices are bad, and so are too many sneakers. As Sanders told CNBC'S John Harwood, on the day he officially announced his candidacy:

If 99 percent of all the new income goes to the top 1 percent, you could triple it, it wouldn't matter much to the average middle class person. The whole size of the economy and the GDP doesn't matter if people continue to work longer hours for low wages and you have 45 million people living in poverty. You can't just continue growth for the sake of growth in a world in which we are struggling with climate change and all kinds of environmental problems. All right? You don't necessarily need a choice of 23 underarm spray deodorants or of 18 different pairs of sneakers when children are hungry in this country.

The literal implication of that last sentence is that there some kind of a national trade-off between antiperspirant/Air Jordan variety and food for children. This makes sense if you believe that the government should be allocating the resources in the economy -- in this case, directing fewer of them to personal hygiene and footwear and more to child nutrition.

It makes less sense if you look at economic history.

All sorts of new brands and styles of deodorant have come onto the market in recent decades: roll-ons, clear sticks, dry sprays. Axe. Walmart.com doesn't list 23 items under deodorant - it lists 1,953. And yet, for all those choices, Americans spend substantially less of their incomes - about 36 percent less - on personal hygiene products today than they did a half-century ago.

Justin Sullivan / Getty Images Justin Sullivan / Getty Images

In part, that's because the price of those products is rising slower than inflation overall. The consumer price index increased about 2.4 percent a year over the last 15 years. The price index for the subset of personal care products that includes deodorant increased just 0.2 percent a year. Underarm dryness is getting cheaper, relatively speaking.

The same is true of shoes - even more dramatically. Americans spent 8 percent of their earnings on apparel and footwear in 1959. They spent 3.2 percent on it in 2009. Food is the most dramatic drop of all, from 19.4 percent in 1959 to 7.8 percent in 2009.

This isn't to say middle-class families have more money to spend these days on luxuries - they don't. What's consumed much more of our national income over the last 50 years are housing, financial services and, especially, health care.

Sanders has a lot to say about finance and health care, guided by a general belief that more government intervention in those markets would lower prices for everyone. He also has a lot of criticism for the free-trade policies that have pushed down prices for some consumer goods, such as shoes, while driving U.S. jobs overseas.

It's hard to see how deodorant helps him make any of those cases, especially when it's gotten easier for poor people to buy it.