§ 43. Discrimination by labor organizations prohibited. As used in
this section, the term "labor organization" means any organization which
exists and is constituted for the purpose, in whole or in part, of
collective bargaining, or of dealing with employers concerning
grievances, terms or conditions of employment, or of other mutual aid or
protection. No labor organization shall hereafter, directly or
indirectly, by ritualistic practice, constitutional or by-law
prescription, by tacit agreement among its members, or otherwise, deny a
person or persons membership in its organization by reason of his race,
creed, color or national origin, or by regulations, practice or
otherwise, deny to any of its members, by reason of race, creed, color
or national origin, equal treatment with all other members in any
designation of members to any employer for employment, promotion or
dismissal by such employer.