Powell’s Books, which bills itself as the world’s largest independent bookstore, is a Portland, Oregon, institution. (Though I’ve always been more partial to nearby Cameron’s.) Its popularity among Portlanders ranks up there with bikes and beer. But now Powell’s finds itself in direct conflict with another Portlandian passion: big government.

This November, Oregonians will vote on the largest tax increase in the state’s history. Measure 97, which is being promoted by Our Oregon, a public-employee-union-funded outfit, would impose a 2.5 percent tax on gross sales for businesses who book more than $25 million a year in revenue. Note, again, that’s a tax on gross sales, not net income. That means that low-margin businesses would be deeply harmed by the tax. Low-margin businesses like . . . well, come to think of it, the new and used books trade.