“ Sections 10 (a) and 2 (7) of the Labor Act empower the Board to prevent 'any person' from adversely 'affecting commerce' by unfair labor practices 'tending to lead to a labor dispute burdening or obstructing commerce or the free flow of commerce.' The Board found that Howell's unfair labor practices tended to do this. Among others, the following facts underlie that finding:
Howell bought its new Chevrolets from a General Motors assembly plant located in California and its spare parts and accessories were delivered to it from General Motors warehouses in California. ”