Brian Snyder / Reuters

On September 30, the Chicago Tribune awarded its presidential endorsement to the Libertarian candidate Gary Johnson, a political cypher who is polling around 8 percent in national polls, which would translate to about 10 million votes in November. Johnson’s support is particularly high among young people. According to a recent George Washington University Battleground poll, Johnson draws 18 percent of Millennials, nearly as much as Donald Trump (26 percent) and more than a third of Hillary Clinton’s support (46 percent).

Johnson’s chief advantage in this election is the possession of a surname that isn’t Trump or Clinton. The two major parties are now led by the two most unpopular major-party candidates in modern history. The cases against Clinton and Trump are well known, but the case for Johnson requires, well, a case for Johnson. And on this score, the third-party candidate has done little to distinguish himself—and quite enough to establish that, at least in this contest, America’s third-party lockout doesn’t deserve its historic breakthrough in five weeks.

Take Johnson’s bungling of foreign affairs. His level of expertise would be appropriate for an amiable CEO of a medical-marijuana company, but it's several standard deviations below the minimum viable threshold to be commander-in-chief of the world’s most significant military power. Johnson’s infamous “What is a leppo?” gaffe on MSNBC was compounded when he failed to name a single world leader in a televised town hall several weeks later on the same network. But more than an Aleppo moment, or an Aleppo month, Johnson suffers from an Aleppo mindset, a proud lack of curiosity about foreign affairs lurking behind an attractively simplistic rejection of military interventions.

Domestic policy is Johnson’s calling card, and the candidate is well known for his laissez-faire attitude toward regulating guns and pot. The Chicago Tribune singled out for praise Johnson’s sensible approach to the deficit and economic growth. "We wish the two main parties had not run away from today’s centrists,” the editorial’s authors wrote.

But far from “centrist,” the Libertarian candidate’s economic ideas are so radical they make Trump seem downright moderate. He would abolish federal income taxes, replace the current tax code with a more regressive national consumption tax, cut Medicare and Medicaid by 40 percent, push for a constitutional amendment to forbid the U.S. to run deficits even during downturns, ban federal bailouts of states, and seek to eliminate the Federal Reserve.

This is worse than fiscal irresponsibility. These ideas aren't politically or even morally responsible. Taken together, they could trigger a recession by taking hundreds of billions of dollars out of the economy, handcuff the federal government’s ability to stabilize the private sector, and throw millions of adults off health insurance, creating a needless economic crisis while whistling under the banner of economic freedom and choice. “Johnson is proposing an immediate fiscal tightening of 3 percent of gross domestic product,” the Washington Post’s Matthew O’Brien wrote. Without the Federal Reserve to buttress the downturn, O’Brien projected that the ensuing recession could push unemployment back above 7 percent.

Johnson would say that his policies are necessarily bold to confront the dangers of U.S. debt. But his presidency might author a kind of Greek tragedy in America—the sort where the heroes, acting to prevent a certain calamity, ironically bring about that very catastrophe. To keep the U.S. from becoming a bloated welfare state “just like Europe,” Johnson would pinch the economy in austerity's straitjacket, drive up unemployment, and purposefully withhold any economic stimulus, which would make the U.S., well, just like Europe.

The U.S. is not looking at an imminent debt crisis. Still, the rising cost of health care combined with the aging of the population will require that the U.S. government spend more on Medicare and Social Security than current tax levels can support. Just as there are many diet plans that don’t involve absolute starvation, there are many deficit-reduction strategies that don’t require the U.S. to cut taxes on the rich, raise taxes on the poor, and take away the federal government’s two best weapons during recessions—monetary easing and deficits. A sensible debt-reduction plan might look quite a lot like the opposite: Taxes on the rich might go up a little bit, federal benefits might have to be reduced or means-tested, and technological advancements and insurance-policy changes could slow the growth of health costs.

From a certain perspective, Johnson’s appeal to young people isn't a surprise. His most well known policy stance—leave people alone, and let them smoke pot—certainly has a constituency. His high numbers among Millennials suggest that he has attracted some positive looks from erstwhile supporters of Bernie Sanders. Like Sanders, whose bed head became an iconic symbol of his authenticity, Johnson similarly comports himself with the demeanor of somebody who has been recently jostled out of an afternoon nap and couldn’t lie to you if he tried.

But on policy, the two could not be more opposite. Sanders, a democratic socialist, proposed to raise taxes by historic sums and spend hundreds of billions of dollars to nationalize health insurance and make college free. Johnson’s plans are the complete reverse: He has proposed to eliminate the federal income tax code, unwind 100 years of anti-poverty and health-insurance programs, and shutter the Department of Education.  His plan would almost certainly raise the cost of college for many middle-class teenagers and 20somethings who rely on federal loans and grants, and his repeal of Obamacare would immediately boot tens of thousands of them off their parents’ health plans.

Beyond his jovial demeanor and admirably passionate anti-interventionist position, Johnson puts a likable face on a deeply troubling economic policy. Scrapping the Federal Reserve while cutting federal spending by 40 percent, while eliminating federal income taxes and trying to institute a new consumption tax would have a predictable effect: It would take hundreds of billions of dollars out of the economy, likely triggering a recession, while shifting the burden of paying for what’s left of the federal government to the poor just as unemployment started to rise, all the while shutting off any possible monetary stimulus that could provide relief to the ailing economy.

Given the electorate’s deep frustration with both the political establishment and the candidates chosen by the two major parties, 2016 is theoretically the perfect year for a third-party candidate to break through. But Gary Johnson’s economic ideas are neither theoretical nor perfect. They are real and simply disqualifying.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.