Well, I looked up the abilities for the various political parties, and what they would cost to purchase in their respective ability points, and I came up with this ranking:
1st. Technologists 5 pts
2nd. Universalists 4.5 pts
3rd. Industrialist, Pacifist, Mercantile 4 pts
4th. Populists, War Party 3.5 pts
5th. Federalists 3 pts
So it looks like the technologist party presents the best overall value. (Just like real life
)