( CNN ) -- It 's been a grueling campaign . You just want to sit down with a bowl of popcorn and find out who will be president for the next four years . So when will we know ? Technically speaking -- who the heck can say ? With a race that went into Election Day neck and neck , and plenty of questions about how key battleground states will play out , it 's reasonable to assume a long night is in store . What to watch for . It could be even longer if the election ends up balanced on the edge of a razor-thin vote in Ohio or if voting irregularities spark legal challenges in any of a number of critical states . Either situation could drag out the decision until mid-November or even longer , analysts say . Whatever happens , some indications should begin to trickle in now that the first waves of poll closings have come , ending voting in Virginia , Florida , Ohio and other key states . West Coast states and Hawaii will stop voting at 11 p.m . ET , and the last Americans will cast their ballots in Alaska by 1 a.m . ET Wednesday . The first place to look : Virginia , according to analysts . But the reporting of results was paused after 7 p.m. because many voters remained in line after the scheduled poll closing time , the state Board of Elections said . When results do come in , Prince William County will be a key indicator , CNN chief national correspondent John King said . `` One of the first things I 'll look at are the margins in the northern Virginia suburbs closest to Washington , D.C. , especially Prince William County , '' he said . Drama awaits in battleground states . `` If Gov . Romney is ahead or at least in play there , it means Virginia is in play , and we could have a long , competitive night , '' King said . `` If he 's not in play , it could be over before we even get to the Central time zone . '' CNN 's chief politcal analyst , Gloria Borger , agreed that Virginia will have a lot to say about what happens later . `` We have to look at Loudoun County in Virginia , and if the president were to win Virginia , obviously , the path to 270 is a lot easier for him , '' she said . `` But if Mitt Romney wins Virginia , it could be a much longer night . '' CNN political reporter Peter Hamby said that results from early and absentee balloting in Pasco County , Florida , could also offer a tantalizing glimpse of what the night may hold . Barack Obama won the early and absentee vote in the slightly Republican-leaning county in 2008 . If Obama comes up trailing when those early votes are posted soon after polls close , it could indicate the president might have trouble carrying Florida and its crucial electoral votes , according to Hamby . Frum : U.S. voting system is a disgrace . If Ohio becomes key to the election , it 's possible that bag of popcorn is n't going to hold you . If the margin separating Romney and Obama is particularly thin , the election in that key battleground state could ride on absentee and provisional ballots . And that could keep the nation in suspense for a whopping 10 days . Ohio provisional ballots hold key . That 's how long Ohio law gives poll workers to check the eligibility of provisional voters . Ohio has one of the nation 's highest rates of provisional voting , with 211,000 cast in 2008 , according to Ohio Secretary of State Jon Husted . About 40,000 were later thrown out . Husted says he thinks the election in Ohio will hinge on the state 's central counties , and the results will be known before midnight . `` I really believe that we will be able to project a winner tonight , '' he said . `` I think that people will have to stay up past their bedtime to be able to do that . But it 's likely that we 'll know by the end of the evening . '' Popular-electoral split is possible . The worst nightmare scenario is a redux of 2000 , when the nation suffered through weeks of uncertainty amid recounts and legal challenges surrounding the vote in Florida . And , sorry to say it , as tightly contested as this race is , it is a possibility , analysts say . `` Between provisional balloting , absentee balloting and voting technology , I think there are untold different ways that this is a tense , contested election , '' said Rebecca Green , co-director of the Election Law Program at William & Mary Law School . `` It 's pretty certain there 's going to be some litigation when this is over on November 6 . '' As we said -- who knows ? Election 2012 : Projections . CNN 's Bill Mears contributed to this report .
NEW : Reporting of results paused in Virginia . Presidential results could be delayed if battleground Ohio is particularly close . Comment: Virginia could be an early indicator , CNN 's John King says .