Matthew Continetti of the Washington Free Beacon focuses on Chicago schools’ dismal fiscal picture.

“The fact is there is no more money. Period,” says Chicago mayor Lori Lightfoot.

She’s talking about the teachers’ strike that has paralyzed her city’s public schools—enrollment 360,000—for the past week. The public employee union is demanding more: more money for salaries (only eight states pay teachers more than Illinois), more support staff (Illinois ranks first in spending on administrators), more teachers per student. Their cause has attracted national attention. Elizabeth Warren joined the picket line.

Which is ironic. Lightfoot is not some stingy Republican. Nor is she a centrist Democrat like her predecessor Rahm Emanuel. She’s as progressive as you can get. But she now finds herself in the same position as many of her political brethren: facing criticism for failing to reconcile the contradictions in the left’s agenda.

Lightfoot has discovered that there is no limit to the appetite of the constituencies generated by government spending. She has learned that the special interests bargaining for higher benefits also desire policies that make such benefits unattainable. I hope she’s taking notes.

Chicago Public Schools has run a deficit for the past seven years. Why? Pensions granted to earlier generations of teachers are expensive. And the cost is growing. A quarter of the school budget is devoted to benefits—money that can’t be spent on classrooms, facilities, and instruction. Expect that number to rise as America goes gray and the bill comes due for the promises we made to ourselves.