Maryland and especially its biggest city, Baltimore, have long been aggressive in using powers of condemnation to assemble land for subsidized megaprojects. As Stephen J.K. Walters and Louis Miserendino showed in a 2008 paper, the giant projects have regularly flopped, been enmeshed in political cronyism or both.

But that’s only the start of the state’s smash-’n’-grab approach to the use of eminent-domain power. Maryland has made a habit of using eminent domain against targets that go beyond real estate and fixed property...