However, there are two reasons why this is actually a lie.

1. Zaphod has recently stolen a large and very valuable spaceship, the Starship Heart of Gold. This will doubtless terminate his term as President.

2. The best person to rule the galaxy is someone who doesn't want to do it. The person who is actually in charge is not aware of his pivotal role in galactic politics, and spends much of his time talking to a cat.

Zaphod Beeblebrox may have figured this out, and it may have something to do with point one above, and his subsequent visit to the dead planet of Magrathea.