Reasons for differences in the change of Politics and Economies in Spanish and Portuguese Colonies

Political

The reason for the difference between political changes in the Spanish and Portuguese colonies was that they colonized completely different lands. Spanish conquerors were able to conquer the natives and organize a labor force to build their American empire, which the Portuguese weren't able to do. Instead, they had to bring in African slaves, which led them to compete with other Europeans, since Europeans also needed supplies of slaves.

Economic

The reason for the difference between economic changes in the Spanish and Portuguese colonies was that in Spain, the profit came mostly from mining silver. This silver contributed to European economy as well, since Spanish kings took 1/5 of it. Therefore, they did not compete with other European states, but rather supported them with silver. Meanwhile, the Portuguese derived money from sugar production, which is a hard business with little profit. The European states also produce sugar, so the Portuguese, already with their little profit, had a reason to compete with the European states to increase their revenue.