Stuart Rothenberg, who has served as a political analyst for CNN and CBS News, is editor and publisher of The Rothenberg Political Report, a nonpartisan political newsletter. Nathan Gonzales is the publication's political editor.
CNN's Electoral Map shows Florida, North Carolina and Ohio as battleground states.
(CNN) -- With the presidential campaign and more than 75 competitive races for the House and Senate, keeping track of it all on Election Day can be a bit overwhelming. But focusing on three states will provide a window through the November 4 election chaos.
No other state provides as much excitement up and down the ballot as North Carolina, where the polls close at 7:30 p.m. ET.
Sen. Barack Obama is making a strong bid for the state's 15 electoral votes, with recent polls showing him in a dead heat with Arizona Sen. John McCain in the presidential race.
If Obama wins North Carolina, he's probably also won Virginia and is well on his way to the Oval Office. Watch more on the state of the race »
Down the ballot, Democratic state Sen. Kay Hagan has a narrow advantage over incumbent GOP Sen. Elizabeth Dole. But Charlotte Mayor Pat McCrory, a Republican, is neck and neck with Lt. Gov. Bev Perdue, a Democrat, as he seeks to become the first Republican governor of the state in decades.
After a narrow win in 2006, GOP Rep. Robin Hayes is now the slight underdog against teacher Larry Kissell, a Democrat, in the 8th Congressional District. Hayes is the type of resilient incumbent who normally fends off challenges, but the anti-Republican wave might prove to be too much to overcome.
Obama and McCain are also battling for Ohio, where no fewer than four congressional seats are in play. Democrats are seeking to overcome their disappointing showing in 2006, when they picked up only a single GOP seat after targeting multiple districts. The polls in Ohio close at 7:30 p.m. ET as well.
Recent public polling shows Obama opening a narrow lead in Ohio, whose 20 electoral votes are a must-win for any GOP presidential nominee. Watch the latest on battleground state polls »
Republicans are likely to lose two open congressional seats in the state (the 15th and 16th Districts), a microcosm of their problems with open seats nationwide. Cincinnati-area GOP Rep. Steve Chabot is extremely vulnerable in the 1st District, even though he's run a good campaign.
GOP Rep. Jean Schmidt is also vulnerable but represents the very Republican 2nd District and faces a weak opponent, even if she isn't particularly strong herself. Republicans missed an opportunity in the 18th District, lost in 2006 because of GOP Rep. Bob Ney's ethical problems, by failing to recruit a good candidate.
And it appears that Obama has a slight advantage in Florida (27 electoral votes), and up to a half-dozen congressional incumbents could lose. Polls in Florida close at 8 p.m. ET, still making it one of the earlier states.
Democratic voter registration has surged statewide, and Republican Reps. Tom Feeney (24th District) and Ric Keller (8th District) are underdogs for re-election.
Brothers/Reps. Lincoln Diaz-Balart (21st District) and Mario Diaz-Balart (25th District) are locked in tight re-election battles.
There are, however, two bright spots for Republicans in the Sunshine State.
Republicans are likely to take back the 16th District after Democratic Rep. Tim Mahoney admitted multiple affairs. And Rep. Vern Buchanan, a Republican, is favored to win a second term in the 13th District.