Whoever can afford to buy it by raising the most money and selling the office with promises beforehand.
Does it really matter in the end anymore? It's like "office speak". Once someone made a stupid comment to be stupid, like "it's a slam dunk". Then, people forgot that it was a joke and took it seriously. Then people were afraid to be on the outside by not using the term(s). The same with the US presidency anymore IMO. It's blah-blah-low taxes-blah-no more war-blah-abortion-blah-no abortion-blah.
It's government by soundbite and no one really seems to care - and if they do, have realized too late that the office was sold long ago. People used to have beliefs and convictions, but I think that those were auctioned off as well. It's about a hollow victory and an office that any respectable, honest, decent person wouldn't want.
I'm fed up with it and dread having to hear about it, and read about it here, in a growing crescendo for the next 2 years.