How is legislation like this any different than pro-union legislation? It benefits workers in a particular industry the expense of consumers who bear higher costs.
Tariffs raise the cost of goods or services. Unions to the extent they have the power to increase wages (they don't really except in highly oligopolistic industries, or monopolistic ones, the premier example of which is government), also increase the cost of goods or services. Just how much in either case is a subject of fierce debate (how much is a cost on capital and how much on the consumer?), but it is clearly more than zero or a de minimus amount.
