Gov. Wolf is on a mission to lift the minimum wage from $7.25 to $12 per hour. In his quest, he has rolled out all the same arguments that Democrats use every time a minimum-wage hike is at hand: a family of four cannot afford the basic necessities of life on a single minimum-wage salary; the state will collect more tax revenue if the wage is raised; and of course, "won't someone please think of the children."

But why do Democrats like Wolf really love fighting for a higher minimum wage?

The answer isn't hard to find once you get past the feel-good rhetoric of this issue. As always, naked self-interest is the strongest motivator.

Everyone knows that raising the minimum wage will, in fact, make life better for the people who see their wages go up. That is indisputable. But what politicians gloss over is that raising the minimum wage will also make life much, much worse for the people who lose their jobs as a result of increased costs to business owners.

When you require that people pay more for something, they buy less of it. This is as true for employers hiring labor as it is for consumers buying anything from homes to fast food.

In the end, raising the minimum wage only helps those workers who could have earned more anyway by shopping around for a better job. But the most vulnerable workers - those with the least skills, least experience, and least education - can't earn more by shopping around because they are already being paid what they are worth.

Raising the minimum wage doesn't force employers to pay vulnerable workers more. It forces employers to let them go.

But Wolf would prefer that you didn't think about those people. He would prefer that you only thought about how "business" will have to pay for the wage hike - ignoring the fact that every cost a business incurs is ultimately paid by people. He would prefer you think this way so you don't notice what he's really doing: buying votes. First he buys the votes of people who believe they will benefit from the minimum-wage hike, then he buys the votes of people whose emotions outwork their reasoning.

But that's just the beginning. He also buys the votes of a group of people who do not come close to working for the minimum wage but whose wages are nonetheless tied to it. And understanding this goes a long way toward understanding why the Democratic Party and labor unions have been in bed together so completely and for so long.

How completely?

According to the nonpartisan Center for Responsive Politics, labor unions donated almost $200 million to politicians in the 2016 election cycle. On average since 2000, 91 percent of those political donations have gone to Democrats. No other special-interest group gives so lopsidedly to one party. Even the oil and gas industries - long vilified as being in bed with the Republican Party - only give 83 percent of their donations to Republicans, on average.

In exchange for 91 percent of their political donations, part of what labor unions get from Democrats is ongoing pressure to raise the minimum wage. According to the United Food and Commercial Workers International Union, union contracts often peg members' wages to multiples of the minimum wage, so as the minimum wage goes up, so too do union wages. Such increases, the UFCW says, are "one of the many advantages of being a union member."

And the strategy pays off for unions.

According to a 2004 study in the Journal of Human Resources, lower-wage union workers see their earnings rise following minimum-wage hikes at the same time that nonunion workers lose their jobs. In the end, raising the minimum wage isn't about wresting money from employers and giving it to workers. It's about wresting money from nonunion workers and giving it to union labor.

If we're going to have an honest discussion about the wisdom of a minimum-wage hike, let's start by admitting that the minimum wage has become a mechanism by which politicians buy union votes in exchange for destroying nonunion jobs and raising union wages. "Compassion" has little to do with it.

Antony Davies is an associate professor of economics at Duquesne University in Pittsburgh.

James R. Harrigan is a senior research fellow at Strata in Logan, Utah.