Federal employees who are members of a union have the right to have a union representative present during an interview with management when the employee believes he will be subject to discipline. That is an invaluable right when you are "under the gun" and feel like your job is in jeopardy. Most states that have addressed the issue also allow Weingarten rights to members of public sector unions. But, now, we know that public sector employees do not have that right.
In the decision of City of Round Rock v. Rodriguez, the Texas Supreme Court found that Texas Labor Code 101.001 does not include that right. Chief Justice Jefferson and others dissented. Texas is in the minority of states regarding this important union protection. See the opinion here. Prior lower court decisions affirmed Weingarten rights. Texas law already forbids strikes by public sector unions. Now, the protection from over-bearing supervisors is diminished.