No
What you describe is more commonly called extortion.
Your exactly right but it happens all the time. You know why? Let me show you the madness.
1. A business votes to Unionize.
2. They collect the dues from those who want to be part of the union.
3. The business starts to descriminate against those who arent in the union because its easeyer to fire them as opposed to the union labor.
4. The union refuses to represent the guy who pays no dues.
5. Now both the union and the business are descriminating aginst the non unionized employee.
6. Both the union and the business are sued.
7. The union is busted and the business loses money.
8. The union goes to their state represenatives that they bought off with union dues.
9. The represenative and his buddies vote for legislation that forces everyone to pay dues reguardless of whether they are in a union or not.
10. The unions win and keep bribing polititions and increasing the prices of goods and services until the business becomes so uncompetitive that it has no choice but to move to a diffrent state or go overseas. Currently, moving overseas is leagle while moving to a different state is not. Funny how that works out huh? See Boeing.
And that is how liberty dies ladies and gentlemen. How is this process constitutional? Exactly how can a group of workers demand higher wages, go on strike when they dont get them, and not be fired?