In many situations, voting is not "one person-one vote." For example, the stockholders of a company usually have one vote for each share of stock owned in the company. Thus, some people may have many votes (have much power) while other voters may have only a few votes (have little power). Here we will make matters simpler by looking only at cases where the voting is between two alternatives. For the case of only two alternatives, all reasonable voting methods can be shown to be equivalent to a simple "majority rules." This allows us to remove our focus from particular voting methods and, instead, examine the concept of power in situations where voters' votes carry different weights (so-called weighted voting systems).