Drew DeSilver at Pew:
Most Americans like labor unions, at least in the abstract. A majority (55%) holds a favorable view of unions, versus 33% who hold an unfavorable view, according to a Pew Research Center survey from earlier this year. For most of the past three decades that the Center has asked that question, in fact, Americans have viewed unions at least somewhat more favorably than unfavorably.
Despite those fairly benign views, unionization rates in the United States have dwindled in recent decades (even though, in the past few years, the absolute number of union members has grown slightly). As of 2017, just 10.7% of all wage and salary workers were union members, matching the record low set in 2016, according to the U.S. Bureau of Labor Statistics (BLS). Back in 1983, when the BLS data series begins, about a fifth (20.1%) of wage and salary workers belonged to a union. (Unionization peaked in 1954 at 34.8% of all U.S. wage and salary workers, according to separate data from the Congressional Research Service.)