<P> A candidate must receive an absolute majority of electoral votes (currently 270) to win the presidency or the vice presidency . If no candidate receives a majority in the election for president or vice president, the election is determined via a contingency procedure established by the Twelfth Amendment . In such a situation, the House chooses one of the top three presidential electoral vote - winners as the president, while the Senate chooses one of the top two vice presidential electoral vote - winners as vice president . </P> <P> A state's number of electors equals the number of representatives plus two electors for both senators the state has in the United States Congress . The number of representatives is based on the respective populations, determined every 10 years by the United States Census . Each representative represents on average 711,000 persons . </P> <P> Under the Twenty - third Amendment, Washington, D.C., is allocated as many electors as it would have if it were a state, but no more electors than the least populous state . The least populous state (which is Wyoming, according to the 2010 census) has three electors; thus, D.C. cannot have more than three electors . Even if D.C. were a state, its population would entitle it to only three electors; based on its population per electoral vote, D.C. has the second highest per capita Electoral College representation, after Wyoming . </P> <P> Currently, there is a total of 538 electors, there being 435 representatives and 100 senators, plus the three electors allocated to Washington, D.C. The six states with the most electors are California (55), Texas (38), New York (29), Florida (29), Illinois (20), and Pennsylvania (20). The seven smallest states by population--Alaska, Delaware, Montana, North Dakota, South Dakota, Vermont, and Wyoming--have three electors each . This is because each of these states is entitled to one representative and two senators . </P>

Who is an elector in the electoral college