In a Sunday article for the New York Times, Sarah Leonard argues for socialism. Socialist leaders such as Bernie Sanders and Jeremy Corbyn, Leonard says, are working with a coalition of young leftists to serve millennials.

An editor at The Nation, Leonard's case fixes on three points. First, that millennials need stronger union power in order to attain better living standards. Second, that capitalism has failed. Third, that larger government is beneficial.

Leonard is wrong on each count.

She starts by lamenting that "...there is no left-wing party devoted to protecting the interests of the poor, the working class and the young." Leonard blames declining union influence over political parties. Unions, she says, are the best way to empower the poor, the lower skilled, and the young.

I think not.

At a basic level, unions serve their members, not society. When, for example, a transport union shuts down commuter access to a city, it is not doing so to help commuters. It is doing so to extract wealth from those consumers, via the transport company, and redistribute that wealth to its members. Moreover, when unions demand absolute protections for older workers, they make it near-impossible for companies to hire younger workers. As I've explained, there is a damning correlation between greater union power and increased youth unemployment.

Voters seem to realize this problem. On Sunday, the newly elected president of France won a huge parliamentary majority. His key promise? Unshackling France's labor market from union power.

Leonard does not accept this reality.

Instead, deriding "...precarious and non-unionized labor," she lurches into an attack on the sharing-economy of Uber, AirBnb, and others.

Most millennials take the opposite view. An Airbnb study from last July showed overwhelming millennial support for the industry. Contrary to Leonard's suggestion, conservatives actually have an opportunity to earn millennial support by defending these industries!

Next, Leonard jumps to the crux of her argument: "The post-Cold War capitalist order has failed us..."

"Especially since 2008," Leonard says, "we have seen corporations take our families' homes, exploit our medical debt and cost us our jobs."

Here Leonard implies that "the system," rather than individuals, is responsible for all the ills of the world. It's that favorite socialist trick: do not blame the person in the mirror, blame anyone else. Her attack on the private sector is particularly odd. After all, the private sector accounts for the vast majority of jobs in the United States. Which, incidentally, is one reason why union power is declining so substantially. People believe unions hurt them.

Leonard's final point is the most important. She claims that "within this generation, certain universal programs — single-payer health care, public education, free college — and making the rich pay are just common sense."

The problem here is Leonard's inversion of "common sense."

For one, the U.S. already has one of the world's most progressive tax systems. The top 5 percent of U.S. earners hold 36 percent of national income, but account for 60 percent of total federal tax revenue. Think about that. About 5 percent of taxpayers pay for more than half of the U.S. government.

Still, when it comes to Leonard's "common sense" case for big government, her main failing lies at the intersection of millennials and math. As I noted recently, we already spend far too much. "As the CBO shows... the national debt will reach 106% of GDP by 2035 and 150% by 2047." And that's assuming none of the new spending Leonard calls for! It's a joke. The existing debt already poses big problems. Why double down on failure?

Of course, Leonard is right about one thing. Millennials are increasingly supportive of socialism. And if nothing else, her piece should be a wakeup call for conservatives. Employing math, history, and meaningful dialogue, we must prove why and how socialism would be disastrous.