I read a piece by Charles Baird recently (I can’t remember where I found it). In it he makes a good point. To say that the union movement is analogous to political democracy is more than a little bit of a stretch. Whereas in a non-corrupt political democracy there is a procedure by which new citizens ultimately gain the franchise (i.e. I turn 18, or become a citizen, and then I am able to vote – and have a say on existing policy), the same cannot be said for a union.
In order for a workplace to become unionized, a majority of those voting (not a majority of the workers at a company) on union recognition are required to support its establishment. After that vote successfully takes place, all employees at the company are subject to the collective bargaining agreements that follow. All new employees are automatically a part of the union and all non-voters and all who voted no are similarly required to be part of the union and may not negotiate on their own behalf. Thus, at some companies, it is possible for a union to be in place without a single present member ever having the chance to vote for whether to have the union there or not. I suppose you could argue that there are decertification provisions – but that does not exactly seem analogous to the political process where candidates are up for reelection every several years, regardless of who voted in the past.
To call unions an important part of “workplace democracy” does a disservice to the term. And that ignores the possibility that unions might do some untoward things to prevent other (non-union) workers from competing with them, or from other firms (who rely on non-union labor) from competing with them.