General strikes are infrequently organized in the U.S., because they’re difficult to coordinate, according to Bill Gould, a professor emeritus at Stanford Law. In 1934, 150,000 workers in San Francisco went on strike for four days after police shot into a crowd of picketing workers, killing three and injuring more than 100.

Gould said that such a protest on the national level, though, is relatively unprecedented. He said if it manages to draw wide involvement, Friday’s action could be “pioneering.”

“It is very unusual, and I think it reflects a sense of outrage that so many in the public feel about the behavior of ICE in dealing with what, for the most part, are peaceful protests,” he said. “The very violent and, as we can see, homicidal conduct of ICE in some circumstances — I think there is a general sense of outrage throughout the country about this.”

Gould said that the national shutdown aims to get the attention of the business community and political leaders.

“If it affects business substantially, business, in turn, will turn to political leaders seeking to get those political leaders to reform what workers are grieving about,” Gould said.