It’s worth noting that the AFT national leadership is NOT elected by the membership. That’s typical of most unions.
Here’s how it works. The members elect delegates to the national convention. At the vote the members are usually presented with a single slate of boss-approved delegates. The national offices aren’t even mentioned.
There might be a few “independent” delegates on the ballot as well. And by “a few”, I mean just that. A few.
The slate carries the day 99% of the time. The boss-approved delegates then elect the national leaders.
It’s sort of like the old Soviet system.
Soviet style election. You vote for the candidates the union (party) selects. How very democratic of them.