Detroit is the poster child for economic decline. The city’s policies and politics over the past half-century should serve as a “do not” guide for policymakers across the country. There’s a great deal lawmakers in Washington can learn. The first is understanding that Detroit’s demise was the result of big-government, liberal policies promoted by self-interested politicians and coercive public employee unions. In the wake of America’s manufacturing decline, Detroit enacted policies that drove out businesses and residents. Rather than reduce the size of government as its population shrank, the city instead sought higher levels of government spending. City leaders...