I'm in a union and it has been a great move. My Dad (elder) was a contractor and worked Union men, which most were JW's in good standing. I've talked with some brothers in Unions, and they seldom went to a meeting (Pledge of Allegiance to the Flag and prayer.)
One brother would not sign the paperwork for the Political Action Committee of the Union to take out 3-5 cents (not percent, a nicklel) per hour. I did and didn't think twice, but I wouldn't talk about it because it's no one's business.
Picket lines and strikes are very rare as unions have lost their edge to negotiate. I was asked a few times to distribute flyers for the union because a foreign company was opening an automobile assembly plant and the State Senator didn't want it to go union. The company was from Germany and they actually wanted Union representation as they were familiar with it in their homeland and a few years later, it was unionized. Unions serve their purpose in that they collectively bargain for all members, organize health insurance for their members which the employer will pay, have pension and retirement funds also paid by the employer. The insurance is good and you can work with many companies and your insurance is the same. The union contract that is negotiated with different companies is basic, besides wages, times you get over time, holidays, etc, they have apprenticeship programs, and offer certification and other training.