The Constitution does not guarantee anyone the right for collective bargaining or unions to anyone. Collective bargaining/unionizing is granted as a privilege by the employer. In the case of government employees, it is a sham.
Do you think that any elected official, supported by the union, is going to disagree with their gravy train? You don’t vote against those that funded your campaign. If any bargaining for benefits is allowed for any level of government employees, it should be for basic salary only.
For any government employee that disagrees with me, get out in the real world and try to find a job that gives you all the benefits and job protection you have. For union members, ask yourself how much more your take-home pay would be if you didn’t have to pay dues to some fat cat union head.