COLLECTIVE bargaining became the keystone of our national labor policy with the passage of the Wagner Act in 1935. The central role of this procedure was preserved in the Taft-Hartley  and Landrum-Griffin  Acts. By choosing collective bargaining as the principal instrument of labor market control, Congress sought to remove sources of industrial strife by a method which preserved private determination free from either unchecked employer power or smothering governmental control. An additional attribute of this device has been pointed out by Professor Clyde Summers: Collective bargaining . . . was historically conceived as something more than an ingenious gimmick of economic self-regulation by countervailing power.... Collective bargaining, as a national policy, is intended to be an instrument of industrial democracy and that national policy presupposes that the workers will have a voice through their union in determining the terms and conditions of their employment.