We may know much about tonight’s presidential election early, with polls closing at 7 p.m. in the key presidential battleground states of Georgia, Indiana and Virginia and at 7:30 p.m. in Ohio, North Carolina and West Virginia. All of these states are traditional presidential election red states and consequently come close to must-wins for Sen. John McCain (R-Ariz.). All are relatively electoral-vote rich states, with the exception of West Virginia, which has five electoral votes.

If Sen. Barack Obama (D-Ill.) wins Virginia, which has not voted for a Democrat in a presidential election since 1964 but which is leaning Democratic, he may be well-positioned to win the race, even if he loses all the others. Polls generally show a slight McCain advantage in Georgia, Indiana and North Carolina, and if he loses any of these it will signal that we could be in for a short night and a possible Obama landslide. If McCain sweeps the 7 p.m. battleground states, the race will likely be very close.

In what could be a bad omen for McCain, 6 in 10 voters said the economy is the most important issue facing the nation, according to an exit poll conducted by the Associated Press. Polls during the campaign have consistently shown that voters trust Obama more than McCain to steer the economy. Each of the other issues on the list — energy, health care, terrorism and Iraq — were chosen by less than 10 percent of voters as the top issue.