the closed shop form of union security means that the
Closed shop A pre-entry closed shop (or simply closed shop) is a form of union security agreement under which the employer agrees to hire union members only, and employees must remain members of the union at all times in order to remain employed. This is different from a post-entry closed shop (US: union shop), which is an agreement requiring all employees to join the union if they are not already members.[1] In a union shop, the union must accept as a member any person hired by the employer.[2]
Labor unions in the United States American labor unions benefited greatly from the New Deal policies of Franklin Delano Roosevelt in the 1930s. The Wagner Act, in particular, legally protected the right of unions to organize. Unions from this point developed increasingly closer ties to the Democratic Party, and are considered a backbone element of the New Deal Coalition.