Who would have predicted that the hottest labor dispute of the summer would be between the workers and management of Bernie Sanders’s presidential campaign?

Sanders is a long-time champion of raising the federal minimum to $15 an hour, so his campaign workers assumed they’d earn that level of pay too:

Campaign field hires have demanded an annual salary they say would be equivalent to a $15-an-hour wage, which Sanders for years has said should be the federal minimum. The organizers and other employees supporting them have invoked the senator’s words and principles in making their case to campaign manager Faiz Shakir, the documents reviewed by The Washington Post show.

Now that the media has exposed their apparent double-standard Sanders will take action to ensure his people get the higher pay, right? Well, no.

In a statement to the Washington Post, campaign manager Faiz Shakir sounds a lot like an executive at Wal-Mart, noting that the pay is petitive”—“We know our campaign offers wages and petitive with other campaigns, as is shown by the latest fundraising reports.” But the telling part is that he refuses to intervene on behalf of the workers: “Bernie and I both strongly believe in the sanctity of the collective bargaining process and we will not deviate from mitment to it.”

The Sanders campaign is being chastised for what appears to be a hypocritical stance. But I think that misses the point. What seems obvious is that Sanders cares more about unions than he does his own workers.

The reason many on the left support raising the minimum wage is not so that workers will earn more money but so that union labor will e more attractive. Four years ago, the unions were pressuring local and state governments to both raise the minimum wage to $15 and hour and to give unions an exemption from having to pay the higher wage.

… Rusty Hicks, who heads the county Federation of Labor and helps lead the Raise the Wage coalition, said Tuesday night panies with workers represented by unions should have leeway to negotiate a wage below that mandated by the law.

“With a collective bargaining agreement, a business owner and the employees negotiate an agreement that works for them both. The agreement allows each party to prioritize what is important to them,” Hicks said in a statement. “This provision gives the parties the option, the freedom, to negotiate that agreement. And that is a good thing.”

Union leaders may be arrogant, but they aren’t stupid. They understand that raising the minimum wage will kill jobs—they just don’t want it to be union jobs that disappear. They are more than willing to allow workers to be paid less than $15 an hour provided that a cut of the worker’s paycheck goes to pay their union salaries. They also realize that the mandatory wage increase will have an extortionary effect on employers: “Can’t afford to pay the high minimum wage? Well, if you e a union shop you can circumvent that pesky law. . .”

But notice also what the unions are saying: business owners and employees should have the “freedom” to negotiate an agreement that works for them both. The caveat, union leaders would add, is that this only applies for “collective bargaining.” It doesn’t seem to matter if employees are worse off than they would have been without the unions “help.” That’s why the Sanders campaign mitted to the “collective bargaining process” rather mitted to paying their workers $15 an hour.

If you want to work for the Sander’s campaign you have to join the union. And if you join the union then you have to accept the wages agreed to in the “collective bargaining process”—even if it is lower than the wage you joined the campaign to fight for.

Sander’s campaign is much better off while the employee is much worse off. What really matters—at least to the union leaders—is that the union is better off. They will be are able to keep dues-paying, voting bodies in their union so that other employees can negotiate a higher salary for themselves (and union leaders can continue to get paid).

Shakir says that, “Bernie Sanders is the most pro-worker and pro-labor candidate running for president.” But which side does he take when the interest of the workers and the union clash? We have the answer already. If Sanders was pro-worker he’d simply offer to pay them what he thinks is the “fair wage” (i.e., $15 an hour). But because he cares more about unions than workers, he is refusing to get involved and risk losing the support of Big Labor.

Sanders may not know much about economics, but he certainly understands how political incentives work.