Kentucky and Indiana are the first polls to close Tuesday on Election Night, followed by four states with competitive races that could provide a first glimpse at whether Republicans will take over the House -- and if the new majority will have swept in on a wave or a trickle.
Republicans need 39 seats to gain a majority, but those in the predictions racket have been estimating somewhere between the mid 40s to the mid-60s for GOP pickups.
Fox News is tracking 100 key races that will affect the balance of power, but of those only nine are Republican-held seats and four of those are open.
The so-called wave is a rare occasion in modern politics, but not without precedent. In 1994, the GOP picked up 54 House seats. In 1938, the GOP picked up 71 House seats. Ten years later, Democrats gained 75 seats in the House. In 1966, the GOP picked up 47 seats.
However, the biggest election swing came in 1894, when the GOP picked up 120 seats. That was the all-time high water mark in the House. In those days, there were only 357 members in the House.
Quirky Indiana and Kentucky straddle the Eastern and Central time zones. Polls close in the state at 6 p.m. ET and 6 p.m. CT. But because some polls are still open in the state until 7 p.m. ET, election officials may be reluctant to call a victory until the more western voters in the state can cast a ballot.
Kentucky and Indiana also have critical Senate races to replace retiring Republicans Jim Bunning and George Voinovich, respectively. Kentucky's Senate race between Republican Rand Paul and Democrat Jack Conway has been volatile throughout the contest.
The lesson to take is the earlier the call, the more convincing the win, which could set the tone for the parties. The later the call, the higher the turnout and/or the closer the race.
Among the most vulnerable in Indiana is Democratic Rep. Baron Hill in the 9th Congressional District. He is facing Republican Todd Young, but was up within the margin in recent polling. Voters also may look to the seat held by Rep. Brad Ellsworth, who is running for Senate against Republican former Sen. Dan Coats. The two candidates for Ellsworth's seat are Democrat Trent Van Haaften and Republican Larry Bucshon.
But shortly after those states start counting, polls in Virginia, South Carolina, Georgia, Florida and Vermont close down followed by North Carolina, Ohio and West Virginia -- all three of which have some close contests.
In Virginia, Democratic Reps. Glenn Nye, Gerry Connolly and Tom Perriello are hoping to hang on after riding anti-Republican sentiment into the House in 2006 and 2008. In Georgia, Rep. Sanford Bishop faces an unexpectedly strong challenge from Republican Mike Keown. In Florida, Democratic lightning rod Alan Grayson faces a challenge from Republican Daniel Webster. Rep. Ron Klein also finds himself in a tight race against Republican Allen West.
If some of these flip but others don't -- if, for instance, Connolly keeps his seat -- it could suggest Democrats are performing better than expected. But a turnover in that seat means Republicans are hitting better than expected in the targets they set to take out.
In Ohio, Democratic Reps. John Boccieri, Mary Jo Kilroy and Steve Driehaus are all on the endangered list, but if Rep. Charlie Wilson also goes down to Republican Bill Johnson, the wave may be building.
At 8 p.m. ET, 19 states stop polling and start counting, bringing the total number of states finished balloting to 29 -- or better than half the country. Those states include Pennsylvania, Illinois, Michigan, Connecticut and others with lower profile races -- for instance in Texas and Maine.
Still it's enough to give a clue what color the country is turning -- blue, red or an exasperated shade of purple.
And while this may be the year of mama grizzlies, several Democratic incumbent congresswomen also find themselves in precarious places. In Illinois, Rep. Debbie Halvorson is facing a challenge from Adam Kinzinger. Reps. Kathy Dahlkemper in Pennsyvlania, Suzanne Kosmas in Florida and Carol Shea-Porter in New Hampshire also are in races that will be tracked for GOP success.
After that, Arkansas closes at 8:30 p.m. ET. The open seat held by retiring Democratic Rep. Marion Berry is up for grabs, but all eyes are likely to be on Sen. Blanche Lincoln, who has been polling behind Rep. John Bozeman for months to keep her seat. Bozeman's seat is considered in pretty good shape as a Republican keeper.
At 9 p.m. ET, New York, Louisiana, Kansas, Colorado, Michigan, Wisconsin all close. Aside from two closely watched Senate races in Colorado and Wisconsin, the states also have some tight House races, including Colorado Rep. Betsy Markey, who is trying to wave off Republican Cory Gardner. Louisiana is also a potential setback for Republicans as Rep. Joseph Cao finds himself imperiled against Democrat Cedric Richmond.
Vacant seats are also an opportunity for pickups. In Michigan, Democratic Rep. Bart Stupak has retired, and in Louisiana, Rep. Charlie Melancon is running for Senate against Republican incumbent David Vitter. In Wisconsin, retiring Appropriations Committee Chairman David Obey may see his seat turned over to Republican Sean Duffy or it could stay in Democratic hands belonging to Julie Lassa.
Back East, former Orleans band member and New York Rep. John Hall will start facing the music. Rep. Bill Owens will also find out whether the special election he won last year to fill Army Secretary John McHugh's seat was just a fluke.
By 10 p.m. ET, Arizona will shut down polling as will Nevada and Idaho, where Rep. Walt Minnick found himself in a surprising tussle despite initially being a Tea Party-backed Democrat and National Rifle Association favorite.
Nevada's initial results may come from early voting and absentee ballots. More than half the voters -- or 290,000 people -- in Clark County, where Las Vegas sits, have already cast their ballots. Another 190,000 voters were expected in the county on Tuesday.
Because of the interest in early voting around the state, Nevada election officials are expecting 65 percent of eligible voters to participate, which is about 10 percent higher than previous off-year elections.
Arizona's lawmakers have also found themselves on the hot seat over the state's illegal immigration law. Even Democratic Rep. Gabrielle Giffords, who criticized President Obama for not doing enough on the border, may find an anti-incumbent sentiment too strong to withstand. Democratic Reps. Ann Kirkpatrick and Harry Mitchell also have tough slogs to overcome.
By the end of the night, the question will turn to the Senate. Three close races are being fought in states west of the Rockies -- California, Washington and Alaska, which, along with Oregon, are among the last polls to close.
Washington may have some early indications, despite its late "poll closing" time because a majority of the state's vote is done by mail. The vote by mail numbers indicate that this "off year" election could be the highest turnout since 1970.
Election officials have taken a look at the turnout from Democrat and Republican areas in the early voting process and found the turnout numbers are slightly down in traditional Democrat strongholds, which could be enough for Republican challenger Dino Rossi to defeat Sen. Patty Murray.
First indications from the state are expected around 11:15 p.m. ET tonight.
At midnight ET, the results will start coming in on the three-way U.S. Senate race between incumbent Sen. Lisa Murkowski, who lost the Republican primary and is running as a write-in candidate, Republican Joe Miller and Democrat Scott McAdams has drawn huge voter interest in Alaska.
Figures just released from the state's Division of Elections show that early voting on this off-election year is nearly double from that of 2006 -- the previous non-presidential year. More than 17,000 people have cast their ballots this time, including absentee ballots.