In just a little more than a week, all of the ballots will be cast and counted in the 2014 midterm elections. While most prognosticators believe the Republicans will have little trouble keeping control of the House of Representatives, a number of polls show the battle for control of the U.S. Senate is still very closely contested.
Here is a preview of the struggle for Congress during President Barack Obama's final two years in office:
U.S. House of Representatives
Republicans control the House 233-199 with three vacancies -- one Republican in Virginia and two Democrat in North Carolina and New Jersey. All 435 seats are at stake in 2014. Terms for those elected will run from January 3, 2015 to January 3, 2017.
Democrats control the Senate 53-45, plus two independents vote with Democrats. Republicans need six seats to take control.
Thirty-six seats are at stake on Nov. 4. Thirty-three are up in the normal election cycle. Three are special elections -- Hawaii, Oklahoma, and South Carolina -- created by death and retirement.
The terms for those elected will run from January 3, 2015 to January 3, 2021.
Here is the breakdown of the races, beginning with those most likely to change hands from Democrat to Republican.
South Dakota -- Rick Weiland (D) vs. Larry Pressler (I) vs. Mike Rounds (R)
Rounds, the current governor, was heavily favored to flip the seat vacated by retiring Democrat Tim Johnson. But Democrats pumped money into the candidacy of former GOP Sen. Larry Pressler, running as an independent. Rounds is still likely to win.
Montana -- Amanda Curtis (D) vs. Steve Daines (R)
Democrat John Walsh was appointed to fill the seat vacated by retired Max Baucus, but he quit the race in August due to fallout from a plagiarism scandal and was replaced by 34-year-old newcomer Curtis. The GOP should take the seat away with Daines, a 5th generation Montanan.
West Virginia -- Natalie Tennant (D) vs. Shelley Moore Capito (R)
Capito is way ahead in the race to replace retiring Democrat Jay Rockefeller in one of the most anti-Obama states in the nation. The daughter of popular former Gov. Arch Moore, Capito could become a star in the battle to open U.S. energy resources, especially coal.
If Republicans win those three seats, they are only three seats away from capturing the Senate, provided they don't lose any states of their own.
That leads to Kansas and Georgia.
Kansas -- Greg Orman (I) vs. Pat Roberts (R)
Veteran Sen. Roberts may be the most endangered Republican after a strong conservative primary challenge. After the Democrat in the race dropped out, Roberts now faces an independent who won't say whether he'd vote for Harry Reid as majority leader. That could hurt Orman in heavily Republican Kansas. Several polls show Roberts leading after reinforcements Bob Dole, Jeb Bush, and Sen. Ted Cruz, R-Texas, showed up on his behalf. But he still trails in some polls and is in an uncomfortable position for an incumbent.
Georgia -- Michelle Nunn (D) vs. David Perdue (R)
Democrats hoped the daughter of legendary Georgia senator Sam Nunn could replace retiring Republican Saxby Chambliss. She hit businessman Perdue hard on the issue of jobs outsourcing, and she's kept the race at a virtual dead heat. If no one gets over 50 percent the two face off again in January, and Georgia voters may have to decide if they'll be the ones to re-elect Harry Reid as majority leader.
The next tier of states where the GOP could take away seats:
Alaska -- Mark Begich (D) vs. Dan Sullivan (R)
Incumbent Begich is battling uphill in Republican territory. The race remains close, but Sullivan, with a moderate label, is hard to tag. Begich is hanging tough despite his vote for Obamacare and his heavy pro-Obama voting record. He's had some success distancing himself from Obama, calling the president "not relevant." When many Alaskans discover their health premiums are canceled in the final days, it could hurt Begich, but maybe not.
Arkansas -- Mark Pryor (D) vs. Tom Cotton (R)
Cotton, an Iraq veteran, has a small lead over Pryor, who voted for Obamacare in a state that is turning more red every election. Still, the race is very close, and if the most recent polls are accurate, it may not be the runaway for Cotton that it looked to be a month ago.
Louisiana -- Mary Landrieu (D) vs. Bill Cassidy (R) vs. Rob Maness (R)
In another southern state where Obama isn't popular, Landrieu proudly says she'd vote for Obamacare again. Louisiana has a "jungle primary" in which many candidates compete on Election Day. The top two have a December runoff if no one gets more than 50 percent. That's where Landrieu could be in real trouble, meaning Senate control could be up in the air until December -- or later, depending on Georgia. Note: Sarah Palin and a number of conservatives are supporting military veteran conservative Rob Maness.
Iowa -- Bruce Braley (D) vs. Joni Ernst (R)
Joni Ernst, another Iraq veteran, climbed to fame with a brilliant primary ad citing her experience castrating hogs on a farm as evidence she knows where to cut pork in Washington. She's hanging in there for the seat in blue Iowa vacated by long-time incumbent Tom Harkin. The race looks like a dead heat at this time, with Ernst holding a tiny lead.
Colorado -- Mark Udall (D) vs. Cory Gardner (R)
Polls show a tight race in a once-red state gone blue. Democrats tried to make hay with Gardner's proposal to sell female contraceptives over the counter, but the race is coming down to other issues and Udall is unable to get more than 45 percent approval. Gardner has run perhaps the best campaign of any Republican challenging an incumbent and maintains a narrow lead in the final week.
North Carolina -- Kay Hagan (D) vs. Thom Tillis (R)
Incumbent Hagan is bucking the anti-Obama sentiment in the Tar Heel State, but she has only a slight lead and could go under in a Republican wave. A Democratic ad blitz savaged Tillis, but he's getting help from a parade of Republican luminaries. It may not be enough, as Tillis angered conservatives by pushing for state toll roads and basically refusing to listen to their concerns. Hagan constantly ties state House Speaker Tillis to the unpopular GOP-controlled legislature. She has a huge money advantage.
Democrats in three blue states and two purple ones are expected to hold on, but if a "wave election" against the leadership of the president and Harry Reid were to materialize, these five states could be in play.
New Hampshire -- Jeanne Shaheen (D) vs. Scott Brown (R)
The transplanted former Massachusetts Sen. Brown is pounding away at his differences with Shaheen on illegal immigration and Obama's foreign policy. Polls show a very narrow Shaheen lead -- with Brown actually leading in one poll -- in the only New England state left, except Maine, with even a slightly Republican tint.
Michigan -- Gary Peters (D) vs. Terri Lynn Land (R)
Some pundits had given up on Land in a race to replace retiring Sen. Carl Levin, but she's within single digits in many polls.
Minnesota -- Al Franken (D) vs. Mike McFadden (R)
Republicans don't think it's very funny that the former comedian Franken is the favorite to win re-election. McFadden, down by double digits, vows to scrap Obamacare and decries Franken's 97 percent pro-Obama vote record. Analysts argue about which polls are accurate -- the ones giving Franken a double-digit lead or the ones giving him a single-digit lead.
New Jersey -- Cory Booker (D) vs. Jeffrey Bell (R)
Veteran conservative Bell has run unsuccessfully in previous Senate races, and incumbent Booker remains the favorite. Still, with little money and a conservative agenda, Bell is organizing street rallies against Harry Reid, and a recent New York Times poll showed him closing from 13 points to 7.
Virginia -- Mark Warner (D) vs. Ed Gillespie (R)
Incumbent Warner defined Gillespie early as a big money lobbyist and portrays himself as a folksy bipartisan Democrat. Gillespie is hitting back on Warner's Obamacare stance and his 97 percent support of the president in Senate votes. Gillespie is down 9 points in one poll. He may close the gap with his alternative to Obamacare and a scandal in the Virginia Senate that could touch both Gov. Terry McAuliffe and Warner, but he remains a longshot.
One more race where the GOP could lose seats if enough went wrong:
Kentucky -- Allison Lundergan Grimes (D) vs. Mitch McConnell (R)
Early polls had Democrats nearly ecstatic that they could knock off Senate Minority Leader Mitch McConnell, who may soon become the majority leader. As the race heads into the final week, McConnell seems to have righted the ship somewhat. Grimes's recent refusal to tell a reporter how she voted for president in 2008 and 2012 won't help in a state where Obama's approval is tanking. McConnell is still not quite out of the woods, though, with some polls showing gap within the margin of error.