The basic principle of the United States (think about the name of our country) is that all states should balance their population (relative power) with their basic identity as a state in a league of other equally-represented states. When the Constitution was being debated this balance of power was holding the delegates back from determining how power should be apportioned. Eventually the Connecticut Compromise was proposed and ratified in 1787. This declared that states would rule the country together through two houses, with the size of each house reflecting each side of the power argument. The Senate was composed of two representatives from each member state regardless of their population, as a way to ensure all states were equally involved in nationwide and international affairs regardless of their size. The House of Representatives governed more domestic affairs and its composition was determined by state size. States send one representative to the House by default, and send an additional representative for every large chunk of citizens they have (I believe the number is 1 million). Seating is capped at 435, but the relative power of large states dwarfs small states. California, for example, has 53 Reps. In the House, California is 53 times more powerful than my own state of Montana, which has all of 1 Rep.
With the balance of power between states determined, all that was left was how to elect the chief executive. Here again small states refused to join the Union unless they were allowed some say in who ran the country. The Electoral College, it was finally agreed, would reflect the state population differences in the House of Reps and the state power balance in the Senate. For every seat on the House and the Senate a state would send one elector to the College. Since the size of the House of Representatives is capped, and the Senate equal, so too is the number of electors a state can send. However the key factor here is relative state power. Montana and California each contribute two electors to the College, which reflects state equality in the Union (the 'United' part of United States) . However California has 53 additional electors to send as opposed to our 1. Effectively this puts the power of California vs Montana when selecting the President at 55-3. As you can see, California's vastly greater population Montana is represented. [continued]