5 election results that could create an electoral college tie.

1.) In the first scenario, which appears to be the most plausible at this point according to current polling in the states, Obama carries Ohio, New Hampshire and Wisconsin, while Romney carries Florida, North Carolina, Virginia, Colorado, Nevada and Iowa.

This is the only scenario that could result in a tie that includes Obama carrying Ohio. In general, if Obama is able to carry this state, the map becomes much easier for Democrats. Polling has shown Obama with a slight lead in Ohio, Wisconsin and New Hampshire recently, and Florida and North Carolina appear to be moving more in Romney’s favor. However, polling has also shown Iowa leaning for Obama.

2.) The second possible path to 269 goes through the West for Democrats; Obama carries Colorado and Nevada, along with New Hampshire and Virginia. Romney wins Florida, Ohio, North Carolina, Iowa and Wisconsin.

3.) The third scenario is similar; Obama carries Virginia, Colorado, Iowa and New Hampshire. Romney wins Florida, Ohio, North Carolina, Wisconsin and Nevada.

4.) The remaining two scenarios seem, at this point, less likely. If Obama wins North Carolina, Virginia and Hampshire, and Romney wins Florida, Ohio, Colorado, Nevada, Wisconsin and Iowa, both candidates will have 269 votes. But recent polls have shown North Carolina tilting towards Romney- ABC News currently rates it “lean Republican.”

5.) In the final scenario, Obama wins Wisconsin, Colorado and Virginia. Romney wins Florida, Ohio, North Carolina, Nevada, Iowa and New Hampshire. Recent polling however, has shown Obama with a small but notable lead in New Hampshire.

In the event of a tie, the decision would in all likelihood be made by Congress. The Constitution dictates that if the Electoral College is deadlocked, the newly seated House of Representatives would select the president while the newly seated Senate would select the vice president.  ABC's Jonathan Karl notes- this would likely result in a Romney/Biden administration.

However, there is an important step in between November 6 and January 6, when the new Congress will be seated.

On December 17, the Electoral College will meet to cast their votes. The Electoral College is made up of actual electors from each of the 50 states plus D.C., and they actually convene after every presidential election to formally select the president. Twenty-six states plus D.C. legally require their chosen electors to vote for the candidate who won their state. However, the remaining 24 states–including the swing states of Iowa and New Hampshire–do not have those requirements, meaning that an elector can decide to go rogue and vote for another candidate.

Let’s say that one of the tie scenarios where Obama wins New Hampshire plays out, but when the Electoral College meets, and a New Hampshire elector decides to cast their ballot for Romney. That would tilt the scales— instead of 269 t0 269, the score would then be 270 Romney, 268 Obama and voila, a president would be chosen.

It’s unclear how plausible this really is. The process of selecting the actual electors varies from state to state, but electors are chosen on Election Day in conjunction with the presidential candidate they support. I.E.–if a voter votes for Obama, they’re also voting for someone who has been selected as an Obama elector. Typically– although again, not always–these electors are individuals who have a history of political activity with one party, which means they’re not likely to be susceptible swing voters.

Elizabeth Hartfield. abcnews.go.com.