how do union presidents gain power and authority?

Answer 1

Their power and authority is based on their members. How they move up through the ranks, might be what you are asking?

That is probably gained best by what they are able to get management to accept and a track record of doing more than others around them.

Answer 2

Money and politics. They have to use politics to get elected. And to manuver themselves into position to be elected.

Once they have the position it is a position of power. They use labor laws which permit the union to automatically deduct union dues from workers. In non right to work states all employees are required to be union members and dues are deducted from their pay whether or not they want to be in the union or not. In non-right to work states they sometimes negociate agreements with employers to shuffle in the union application and authorization to deduct dues into the packet of documents filled out by new employees. Who then uwittingly have the dues deducted from their pay checks.

Then the union president has this vast sum of money collected from members and uses it to support politicians that pass laws that make it even easier to extract dues from workers and the process continues. Its basically organized crime.

Answer 3

By appearing to be the one who is most capable among the contenders