New York ( CNN ) -- Even though the American elections wo n't be decided until the polls close tonight , the Irish bookies late last week started paying off bettors who predicted Republicans would win a majority in the House of Representatives . And they stopped making new bets . That 's a pretty definite statement ! Although I am very confident my party ( Republican ) will win the House , I usually like to wait until the voters have voted before taking any victory laps . Many of my pundit friends have had a field day attempting to analyze , over the last several weeks , the early voting patterns of those of you who have cast ballots already and argue what it all means . I have always been more concerned with the late counting of votes rather than the early voting . And because so many races are so close , this is one election in which every vote can matter . Follow the latest on the election at CNN 's Election Center . There is an old saying in the business : `` We only hold elections to see if the pollsters are right ! '' And if the pollsters are right , it will be a big night for Republicans and a lot of second-guessing at the White House . Certainly viewers will know some trends and results shortly after the polls close . But in other cases , it will be late Tuesday and maybe even sometime Wednesday before we know the final results -- particularly in the Senate , where key Western races may alter the final outcome . Here is what 's at stake : There are 37 Senate races being contested ( 19 Democratic and 18 Republican ) . Fourteen of those seats are open , meaning either the incumbent is not running for re-election or has been defeated in a primary . In order to win a Senate majority , Republicans have to hold Alaska and all their open seats : New Hampshire , Kentucky , Ohio , Florida , Missouri , Utah and Kansas . And they must win 10 Democratic seats . If any of the Republican seats go to Democrats , the Democrats will continue to hold the majority . Everyone has all but conceded two Democratic open seats : the North Dakota seat will be won by Republican Gov . John Hoeven , and the Indiana open seat is likely to be won by former Sen. Dan Coats , also a Republican . More opinion on the election . The most vulnerable Democrats running for re-election are Sens . Blanche Lincoln of Arkansas ; Russell Feingold of Wisconsin ; and Harry Reid of Nevada , the Senate majority leader . The Nevada election is the most heavily watched race in the country , and it has been neck and neck in the polls . Reid 's opponent is Sharron Angle , a Tea Party-backed candidate and former Republican state legislator . This race has gone back and forth , but Angle took a narrow lead going into the final weekend after surviving millions of dollars of negative advertisements . If she wins , this will be the biggest story of the night . The next best chances for Republican gains are the Illinois , Pennsylvania and West Virginia open seats . The West Virginia Senate race between Democratic Gov . Joe Manchin and businessman John Raese has been a back-and-forth contest . If Raese upsets the popular governor , Republicans are in the chase to make the Senate very close . Other vulnerable Democrats are Sens . Michael Bennet of Colorado , Patty Murray of Washington and Barbara Boxer of California . Here is what 's happening in the House : All 435 seats are up , and 43 seats are open ( 20 Democrats and 23 Republicans are not running for re-election ) . In the present Congress , there are 256 Democrats and 179 Republicans . Two seats are vacant . CNN has systematically chosen 100 congressional races to focus on . Fifty are viewed as the most competitive . Four of these are Republican and the rest Democratic . They have listed another 50 House races to watch . Five of these are Republican and the rest Democratic . This is a far larger number than in most midterm elections , but all of these races have shown signs they are competitive . Republicans must win 39 seats to win the majority . If early in the evening , Democratic incumbents start losing in the early returns from states such as New York , Pennsylvania , Ohio and Florida , then it is likely the trend predicted for Republicans to gain a majority in the House will come true . There are 16 vulnerable seats in those four states and another 11 on the watch list . If at the end of the night you see that either the dean of the House -- John Dingell of Michigan who has been in Congress since 1955 -- or Barney Frank of Massachusetts has lost , then you know it 's been a historic election . That sums up the congressional and Senate races , but many states have other contests , including 37 governors ' races ( 19 Democrats , 17 Republicans and one independent up for election ) . Twenty-four are open seats . Republicans are expected to easily end up with a majority of governors . Across the country , there are 6,118 state legislative seats also being contested , along with 160 ballot measures in 37 states . Tune in for what should be an exciting evening . But most of all , go vote ! The opinions expressed in this commentary are solely those of Ed Rollins .
Rollins : Irish bookies already paid bettors who predicted GOP would win House majority . Because so many races are close , this is one election where every vote matters , Rollins says . He says Republicans are expected to easily end up with a majority of governors . If John Dingell or Barney Frank loses , then it 's been a historic election , writes Rollins .