Aleem Maqbool
BBC news, Iowa

tweets, external: Sudden rush at polling station in rural Brooklyn, Iowa. These voters could change power of the Senate #BBCMidterms

As results come in, control of the Senate could be decided by the end of the night - or it could be next year. Two states - Georgia and Louisiana - require run-off elections if no one candidate makes it to 50%. In Louisiana's three-way race, a run-off is almost assured. Georgia may also go to a run-off, putting an election on 6 January, just days after the new Congress is scheduled to begin.

Franz Strasser
BBC News, Wisconsin

Justin Kuto of Minneapolis, Minnesota, tells me that affordable education is important to him in the mid-term elections.

"For what I need, a Republican controlled Senate will make things worse."

The $3.7bn (£2.3b) spent on House and Senate mid-term elections is equivalent to the worldwide box office gross for all 13 Batman films, according to NPR, external.

Senate Minority Leader Mitch McConnell won the male vote in Kentucky by 19 points over Democratic candidate Alison Lundergan Grimes. She held the female vote by only 5 points, according to an ABC exit poll.

Senate Minority Leader Mitch McConnell is projected to have won his Senate race against Democrat Alison Lundergan Grimes, according to an ABC exit poll.

Jon Sopel
North America editor

tweets, external: Remember full coverage of #Midterms2014 starting shortly with @KattyKayBBC and myself #BBCMidterms

Franz Strasser
BBC News, Minnesota

Julie Chapman from South St Paul, Minnesota, says it does not matter to her who controls the Senate.

"Nobody will work together. They used to work together back in the day, but it's become so partisan now that I feel like you can't get anything done."

It would be a huge shock if independent candidate Greg Orman were to win in Kansas - since 1938 the state has sent only Republicans to the Senate. Polls close there in just over an hour.

Image source, Reuters

Rick Klein, Political director at ABC

tweets, external: Dem turnout #COSEN hasn't been lower going back to '92, per prelim exit polls #ABCVote

Franz Strasser
BBC News, Wisconsin

Donna Huppert from Pierce County, Wisconsin, tells me that focusing on the economy can help families get on their feet.

"When you go to the gas pump and the gas is down, it does help. You're feeling a bit of an improvement in the economy."

Tonight's battle is all about who ends up with a majority in the House and Senate. Our graphic on the US front page will keep you up to date with the running totals for both parties.

Sixty four senators are not up for re-election today (32 Democrats, plus two independents who caucus with them; and 30 Republicans) so those seats are already assigned.

You may think it strange that the data has decided the winner of eight House races before the polls have even closed (five Democrats and three Republicans). Those candidates have had to face the voters today - but they have not had to face an opponent. In a one-horse race, victory is guaranteed.

Nada Tawfik, BBC News, New York

tweets, external: Becoming maj leader would be pinnacle of #McConnell's career. KY's longest serving Sen has never had pres ambitions.

Immigration and the Keystone Pipeline - a highly-contested oil pipeline stretching from Canada to the US - will be major issues in a Republican-led Senate, according to Fox News, external.

Republican control of the Senate sets the stage for a massive battle between the parties if a vacancy opens up on the Supreme Court, writes the New Republic's Jeffrey Rosen, external. It's easy to imagine a protracted standoff between Senate Republicans and President Barack Obama over a Court replacement, leaving an empty seat on the bench for an extended period of time.

Image source, AFP

Franz Strasser
BBC News, Wisconsin

Nate Sorwig from Hudson, Wisconsin, says it is fair for Republican politicians to compare Democratic candidates to President Barack Obama.

"A lot of people are unhappy with the direction the country is going in and the fact that somebody has a record of voting with the president, say 90+ percent of the time, they need to be held accountable."

Jeff Zeleny, ABC News Washington Correspondent

tweets, external: In Kentucky, nearly 7 in 10 voters say the country is seriously on the wrong track, based on preliminary exit poll data. #kysen

Kevin Breaux, an independent who voted in New Orleans, told the Associated Press news agency he was hoping for more gridlock in Washington.

"That's a good thing... It's far better than [President Barack] Obama advancing his liberal agenda."

Candidates and political groups have clearly felt they have sympathetic audiences on certain US cable channels, and are targeting their adverts accordingly.

Kanye West, singer

tweets, external: I know it's last minute, but if you haven't voted, please vote today