HOUSTON, United States

The Nov. 8 US midterm elections are just days away, and a possible shift of power in Congress hinges on some extremely tight races.

Thirty-five of the 100 Senate seats are up for grabs during the midterms: 12 Democratic-held seats and 23 Republican-held seats.

The parties are currently split 50-50 in the Senate, with Vice President Kamala Harris holding the tie-breaking vote in favor of the Democrats.

That means Democrats must win 12 seats to maintain control of the Senate.

Here are the top 10 Senate races to watch on Election Day.

Georgia

The showdown is garnering national attention, with two Black candidates running neck-and-neck.

Incumbent fiery Baptist preacher Raphael Warnock became the state's first-ever Black senator two years ago in large part due to a huge Black voter turnout.

This time, Republicans are countering with their own Black candidate in former football legend Herschel Walker, who was hand-picked by close friend and former President Donald Trump.

Walker is facing allegations from two women that he urged them to get abortions, which he has denied, as well as charges that he padded his resume and is not up to the job. Warnock is using those allegations against Walker, which has turned the race into a nasty battle. Despite the mudslinging, the race is a toss-up.

If neither candidate gets more than 50% of the vote, there will be a Dec. 6 runoff, which could briefly postpone the determination of majority rule in the Senate.

Pennsylvania

Democrats are eyeing their best opportunity to gain a Senate spot by flipping Pennsylvania, replacing retiring Republican Pat Toomey.

A fierce battle is taking place between Democratic candidate John Fetterman –

the state's current lieutenant governor – and his Republican opponent Mehmet Oz, better known as "Dr. Oz" from The Oprah Winfrey Show.

Despite popular social media spots deriding Oz as an out-of-touch candidate lacking connections to Pennsylvania, Fetterman's lead waned after he suffered a stroke back in May and the visible effects of his health condition became a target for Oz.

But Oz's stance on abortion and the overturning of the landmark Roe v. Wade decision has become a target for Democrats after he said abortion should not be controlled at the federal level but that "states can decide for themselves," leaving the decision to “women, doctors, local political leaders.”

The last two presidential elections in the state were each decided by barely 1%, so it will come as no surprise if the race goes down to the wire in this key battleground state.

Nevada

Republicans are eyeing this race as one of their key takeover states, with incumbent Catherine Cortez Masto desperately trying to hold onto her seat.

She is facing Republican opponent and Trump supporter Adam Laxalt, who backed the ex-president's unfounded claims that the 2020 election was stolen.

Many voters are dissatisfied with the Biden administration’s efforts to tame rising inflation, with gas prices hovering at $5 per gallon, which is helping Cortez Masto, who in 2016 became the first US Latina senator.

Laxalt is capitalizing on those issues and piling on with the issue of immigration problems and "chaos at the border."

Political strategists are saying the race is too close to call.

Wisconsin

Democrats were hoping to cruise to victory after incumbent Ron Johnson had announced his retirement.

But Johnson backtracked and flipped the script by jumping back into the race.

His Democratic challenger, Wisconsin's current Lieutenant Governor Mandela Barnes, has waged a strong campaign to turn the state from red to blue. The polls have the candidates running neck-and-neck.

Democrats made Wisconsin their biggest target before Johnson decided to run for reelection, so expect another hotly contested race will go to the wire.

Biden carried Wisconsin by less than half a percentage point in 2020, so all eyes are on this race, which could end up with a razor-thin margin of victory for either party.

Arizona

Republicans are trying to take back the seat from former astronaut Mark Kelly, who won a special election in 2020 after the death of incumbent Republican John McCain.

Kelly's Republican opponent Blake Masters was endorsed by Trump and has been getting help from Trump's super political action committee (PAC).

While Republicans believe they have a slight advantage, this race is too close to call.

North Carolina

Democrats are trying to turn the state blue by filling the seat of retiring Richard Burr.

Republican candidate and Congressman Ted Budd was Trump’s first non-incumbent Senate endorsee in the election cycle.

Democratic challenger Cheri Beasley, a former state Supreme Court chief justice, if elected would be the state’s first Black senator.

Beasley is trying to run as the outsider, saying in a recent campaign ad: “Washington politicians like Ted Budd aren’t listening."

North Carolina is no stranger to close elections – Trump won the state by about 1 point in 2020.

New Hampshire

First-term incumbent Democratic Maggie Hassan is fighting for her political life to hold onto her seat.

Her Republican opponent, retired Army Brig. Gen. Don Bolduc, was endorsed by Trump and is taking the battle to the polls even though he has raised virtually no money.

Bolduc does not fit the cookie-cutter Republican profile. He is a Trump critic who supports abortion rights in a blue state that Biden carried by 7 points in 2020.

On the false claims of voter fraud in the last election, he has flip-flopped.

As of Oct. 19, he had raised about $1 million compared with Hassan’s $39 million.

Even with her massive fundraising advantage, Hassan is likely going to be sweating it out to the finish line.

Ohio

Republicans are trying to keep Ohio red by replacing retiring Rob Portman with their own candidate.

But Democratic Congressman Tim Ryan is standing in their way by barraging the airwaves with campaign ads touting that even as a Democrat, he has sided with Trump on issues such as trade.

Republican candidate J.D. Vance was Trump's hand-picked candidate in the state but he has struggled to raise money and unite Republican support after a divisive primary.

Trump won the state by 8 points in 2020, and over the last decade Ohio has trended red.

But this race could end up going to the final ballot on Election Night, which is likely the reason Trump is holding a rally in the state the day before the midterms.

Colorado

Democrats are trying to keep Colorado blue in a hotly contested race.

Incumbent Michael Bennet is no stranger to close races. He won his last reelection in 2016 by 6 points against a Republican challenger the party abandoned.

But businessman Joe O’Dea, the Republican challenger, is providing a much bigger challenge by taking an untraditional approach as a Republican: expressing support for abortion in the early stages of pregnancy and criticizing Trump.

Biden carried Colorado by more than 13 points in 2020, but O'Dea is hoping to flip the script and steal a seat Democrats believe should be safely blue in a race that could be much closer.

Florida

Two-term incumbent Republican Marco Rubio is expected to hold onto his seat, but Democratic congresswoman Val Demings is giving him a run for his money.

Demings, a former Orlando police chief, has touted her law enforcement experience, saying in a recent campaign ad: “The Senate could use a cop on the beat." She has also outraised Rubio in fundraising.

Rubio leads Demings in the polls but the race is garnering political drama because Rubio is campaigning with Trump instead of Governor Ron DeSantis, who is positioning himself for reelection in addition to a possible run for the 2024 Republican presidential nominee against the former president.​​​​​​​​​​​​​​