Labor unions are trying to take back politics in the Midwest

On Labor Day — designated a federal holiday in 1894 to honor America’s labor movement — at least eight Democratic candidates will hold rallies in five Midwest cities to tell workers just how far the country has veered from its pro-labor roots.

In Wisconsin, Gov. Scott Walker (R) has helped turn the state red by decimating public-sector unions. In Iowa, Republicans rolled back an increase in the minimum wage in March. Just last week, Illinois’ Republican governor vetoed a...