The entire planet should fall under the jurisdiction of one government.
because
score: 2
The function of the government is to stabilise society by establishing standards of trade and security. In a highly homogenous/globalised world, where the acts of one group of people affect all, a clear mandate of norms needs to resonate through all human affairs if we wish to progress any further.
This would likely occur as a by-product of the blurring and eventual dissolving of national boundaries through globalisation and free-movement treaties. Specific regions will require regulatory authorities, and these will then form a kind of regional assembly/parliament below the global government.