In the US, a union must represent a majority of the workers identified as potential members of the collective bargaining unit in order to gain that negotiating

In the US, a union must represent a majority of the workers identified as potential members of the collective bargaining unit in order to gain that negotiating status under Federal and State laws. Once recognized through a vote or collection of cards representing a majority, the union can negotiate a contract and labor agreement representing all employees (I’m fuzzy on whether recent judicial decisions have weakened this to just formal union members).