Progressives are changing the Democratic Party’s focus from building stronger safety nets for the disadvantaged to subsidizing everything for everybody. Whereas Barack Obama once appeared radical for subsidizing health-care costs for the middle class as well as the poor, Democrats now promise free college, free health care and more—for everyone. Republicans can’t outspend Democrats, but they can make the case for freedom and against the idea that everything is “free” without sounding like Scrooge.

The Republican ideal isn’t...