It's for the position of Party Organizer. The northern gods get together every century or so and have a big party together (during which they also like to bet with one another), and one of them is selected every millennia to organize them. Currently, the organizer is Thor, and he likes parties with lots of beer and mountains of sausages, and Loki is angling to replace him next time the post is up for grabs because he much prefers parties with drinks with "funny" double entendres in silly glasses with umbrellas in them, and small bite-sized foods stuck on toothpicks.
The vote is slightly offset from the actual millennia because no-one thought they needed the position when creating the world 2.0. It wasn't until 16 years into the task that they felt they needed a bit of a break, and that's when they first voted.
As to why start his campaign to get elected so early, it turns out that Loki is of the same mindset as
Cato the Elder, and feels it the best policy to end up all speeches with this.
Grey Wolf