Well, I grew up in a house where the street facing side was lined with 1/4" steel plate. why? Well, when a union 'brother' says striking over a dime an hour is a waste, refused to march for a particular politician, and said he'd vote to decertify on a proposed decertification election, his other union 'brothers' unload a rifle into the side of my house. Fuck unions. In the early 80's, my grandfather's custom equipment manufacturing company was on the brink of bankruptcy, for a number of reasons. He was open with his workers, no raise this year. We have to get a particular $10mm machine out on time, or the company would have to pay liquidated damages for being late. Well, the union thought that was a great time to strike! Well, it wasn't. They struck so long, at the end of the project, that they missed the delivery. The guys who didn't want to go on strike paid the price with the union agitators - they close thier doors. 150+ people unemployed, my grandpa lost nearly everything. Fuck unions.
I've learned some nuance later in life. Trade unions (pipe fitters, electricians, etc) have my support. I can get guys from the Hall for a job and other than a few slackers, which are easy enough to reject, I can expect a certain amount of production. they also handle the HR part of the tradesmen and let me flex my workforce. Value add.
Public employee unions I am actively against. There's so much wrong with the incestuous way they conduct themselves that I'm not not going to go into it. But I support a constitutional ban on public employee unions. full stop.
Close shops? absolutely not. No way. Unions add NOTHING to this transaction. All the stereotypes about union shops aside, protecting slackers, etc... all true. But the bargain process made me sick the one time I was around it. They were willing to accept reduced pay and time off, to get "check off." (IE, the company withholds the dues from the worker's check.) They don't care about the employees, they care about thier payments. Later, they were brazen about trading grievances for thier cocksuck cronies. (they would not pursue a grievance for one individual, in exchange for the company not fighting a grievance submitted by one of the shop steward's favorites.)
Not to mention the cost! Employee take home was basically flat after the union came, there were some token improvements to thier healthcare options, but the cost of dealing with the union's bullshit exploded... a cost to the company, of which the workers got nothing.
Employers need a credible unionization threat to keep them honest. I get it. But union reform in this country, is long overdue. Right to work is a good step. I'd trade that for card-check. Preventing unions from participating in politics the way they do is another. I think Europe has some good examples of how this can be done well, for the benefit of everyone.