a little history...
The archetypal liberal FDR OPPOSED public unions--
"The process of collective bargaining, cannot be transplanted into the public service," Roosevelt wrote in 1937.
Yes, public workers may demand fair treatment, wrote Roosevelt, but, "I want to emphasize my conviction that militant tactics have no place in the public sector. A strike of public employees manifests nothing less than an intent on their part to prevent or obstruct the operations of Government."
Even George Meaney, long-time head of the AFL-CIO, agreed that it is inappropriate for guvment employees to unionize.