No, closed shops are illegal, but union shops aren't. An employer can no longer agree only to hire people who are already members of a union (that's a closed shop, which used to be legal), but they can force you to join a union after you are hired. If that's the case, if the union terminates your membership, the employer is forced to terminate your employment as well.

(Ironically, the union can force you to pay dues even if you're not a member, but that's a separate matter.)

If an employer chooses to require it's employees be members of a union, I think that's their right. But, I dislike (and think should not be legal) a group voting to unionize and then forcing their agreement onto other employees that don't want to be represented.

To my current understanding, there are 2 stumbling blocks to that way of doing things. 1) Employees can force an employer to deal with a union and 2) the union must cover everyone in the bargaining unit.

In my opinion, ideally both of those things would stop. A union can operate and negotiate on behalf of it's members. The union contract wouldn't cover non-members. And an employer can choose not to hire union workers.

So you're cool with unions enforced by dictators but not unions enforced by democracy?