With election day less than a week away, the electoral college is still perhaps the most influential and simultaneously least understood aspect of American Presidential elections. After tens of millions of votes are cast, only 270 are required to be elected President of the United States. Established under Article II, Section 1 of the U.S. Constitution, the electoral college was later amended by both the twelfth and twentieth amendments to arrive at its current form. The idea is that states vote for the President and Vice President, and the people vote for the legislature. This method was essentially a compromise between those who wanted Congress to elect the President versus those who prefered a nationwide popular vote.

Each state is allotted a number of electors equal to the size of its congressional delegation. For example, Ohio’s 18 electoral votes equal it’s 16 members of the House of Representatives and two Senators. With a total of 538 electors (Washington D.C. is allotted three votes despite having no voting members in Congress) a majority of 270 is required to win election. Though the process varies, electors are generally selected by the political parties at statewide conventions or by each parties central committee’s. On election day, voters choose the electors by casting votes for one of the Presidential candidates on the ballot. With the exception of Maine and Nebraska, all of a state’s electors are awarded to the candidate who receives the most total votes. Maine and Nebraska award electors proportionally allowing these states to award votes to more than one candidate.

The electors meet to cast votes on the first Monday following the second Wednesday in December in their respective states, and send the certified results to Congress. Congress then counts the official tally in a joint session on January 6 following the year of the electors meeting. While there is no Constitutional provision or federal law that requires an elector to cast a ballot based on the popular vote of their respective states, most state and party laws require electors to adhere to popular vote pledges. Additionally, the Supreme Court has traditionally held that electors must vote consistent with the results in their states. In practice, electors generally do not go against the will of the electorate. According the National Archives, the official record keeper of Presidential elections, less than 1 percent of electoral voters have not voted in accordance with the popular vote historically.

Essentially what all of this means is that each candidate is focused on a small number of states that are likely to go either way instead of running nationwide campaigns trying to win the popular vote. Based on a number of recent maps drawn from incessant polling and statistical models, there are between 7 and 9 states still rated as toss-ups in the election (FL, CO, IA, NC, NH, NV, OH, VA, WI). Without the electoral votes offered by these states, President Obama currently has between 237 and 243 electoral votes (NV leans D in some projections) to Governor Mitt Romney’s 191 to 206 votes (NC leans R in some projections).

If there is any confusion as to which states each candidate deems vital to winning the election, look no further than each campaigns schedule over the next few days. Both President Obama and Governor Romney will present their closing arguments in each of the aforementioned swing states hoping to turn that last undecided voter before election day. And if you’re still curious, keep in mind that no republican has EVER won the Presidency without winning Ohio, so expect to see a lot of the Romney campaign in the buckeye state.

To learn more about the electoral college visit the National Archives and to build your own electoral map and lay the path to 270 for each candidate, visit 270towin.com.