Several appear neck-and-neck in the last week before Election Day.

Thirty-five Senate seats are up for grabs when Americans head to the polls on Nov. 3. A key handful of them will be critical in determining whether Democrats or Republicans control the chamber next year.

Republicans currently control the Senate with 53 seats. Democrats and two independents make up the Senate minority with 47 seats.

In order for Democrats to take the chamber back, they’ll have to net four seats in the upcoming election. Republicans can afford to lose up to three and still be considered the Senate majority with the tie-breaking vote of Vice President JD Vance.

Some of the races that were closely watched earlier this year have slid from the spotlight as the election grew near. Republicans seem to have abandoned efforts to unseat incumbent Sen. Jon Ossoff in Georgia and have pulled out of spending in North Carolina, where former Democratic Gov. Roy Cooper now seems poised to best former Republican National Committee Chair Michael Whatley to fill retiring GOP Sen. Thom Tillis' seat.

As both parties prepare for the final leg of the campaign, here are some of the most closely watched Senate races. Michigan: A bitter fight against a progressive newcomer ABC News rating: Lean Democrat Republican nominee Mike Rogers is no stranger to Senate races -- the former congressmen lost his 2024 bid to now-Sen. Elissa Slotkin by less than 20,000 votes.

Rogers is squaring off this time against progressive Abdul El-Sayed, a former health executive who bested a moderate candidate in the Democratic primary.

Republicans have gone to great lengths to frame El-Sayed as “radical" over his support for Medicare for all and his positions on immigration. They've also attacked him for his faith and ethnicity. Rogers has falsely linked him to terrorist groups and President Donald Trump has gone as far as calling him a "vicious, violent jihadist" while urging voters to reject him to "preserve our religion, our values, and our heritage." El-Sayed, who was born to Egyptian immigrant parents in Rochester Hills, Michigan, has denied ties to terrorism and called those characterizations Islamophobic.

El-Sayed told ABC News Live anchor Linsey Davis last week, "They think they can point to my name and my faith and distract us from the fact that we can't afford our gas and we can't afford our groceries." Rogers told Davis in a separate interview the he thought he was making inroads with traditionally Democratic Jewish and Black voters who are wary of El-Sayed.

Michigan has voted for Trump in two of the last three elections, yet Democrats have prevailed in every Senate race since 1994.

Texas: A primary upset puts Dems in the hunt ABC News rating: Tossup Texans have not been represented by a Democrat in the Senate for 33 years, but Democrats say this could be the year that changes.

Texas Attorney General Ken Paxton beat long-time incumbent Sen. John Cornyn in a costly GOP primary runoff thanks to Trump's late endorsement. Paxton, a hardliner and ally of the president, is seen by many Republicans as a harder sell in the general election than Cornyn would have been.

Paxton has had several scandals in his time in the public eye. He was impeached in 2023 on allegations of abuse of office, bribery and corruption but was acquitted by the state Senate. He was indicted on securities fraud charges in 2015 but reached a pretrial agreement with prosecutors just weeks before trial in which he agreed to community service, legal ethics courses and pay $300,000 in restitution in return for not having to admit guilt.

Just weeks before he is scheduled to go to trial on securities fraud charges stemming from theH state indictment filed against him in 2015, Paxton reaches a pretrial agreement with prosecutors to resolve the case. Paxton agrees to complete a series of actions, including doing community service, taking legal ethics courses, and paying nearly $300,000 in restitution. Not required to admit guilt, Paxton releases a statement, saying, "There will never be a conviction in this case nor am I guilty." Democrat James Talarico is a former state representative and Presbyterian seminarian. Republicans have tried to paint the 37-year-old progressive as far-left and radical.

Democrats hope Paxton’s lack of favorability coupled with larger concerns about affordability could be enough to end their three-decade Senate drought.

Republicans are taking no chances, pouring millions into this race and even opted to hold their inaugural midterm convention in Dallas.

The race is the most expensive Senate race in history: Outside groups have contributed more than a quarter-billion dollars to elect Paxton. Over $500 million has been spent on ads in the state, according to AdImpact.

Alaska: 4 candidates, 2 Dan Sullivans Incumbent Republican Dan Sullivan will square off against former Democratic Rep. Mary Peltola and another candidate with the same name in another surprisingly close race.

Alaska’s ranked-choice voting sends the top four vote-getters in primaries to the general election. Peltola is advantaged by being the only Democrat to advance.

In addition to Peltola, Sen. Sullivan faces another opponent on the ballot also named Dan Sullivan, an independent, and Republican Gerald Heikes, who made the final four when the fourth-place finisher dropped out.

Republicans, including Trump, have made a point of reminding voters to check that they’re casting their ballot for the “real Dan Sullivan,” and on Oct. 23 he directed the Justice Department to preemptively sue to block certification of the results if the incumbent narrowly loses. Trump won Alaska by 13 points in 2024.

Ohio: An appointee senator vs. a former one The Ohio Senate race features two candidates fighting for their chance to return to the Senate: incumbent Republican John Husted and former Sen. Sherrod Brown, who lost his 2024 re-election bid to Bernie Moreno.

Husted was appointed by Ohio GOP Gov. Mike DeWine in 2025 to fill the Senate seat left vacant by Vice President JD Vance. This race will determine who finishes out the remainder of Vance’s term until 2029.

This is Husted’s first time on the statewide ballot. Though Ohio has been moving increasingly toward Republicans in recent elections, Husted faces a tough race amid growing concerns about affordability and data centers in his home state.

Brown lost his re-election bid against newcomer Moreno by about four points in 2024, though he outperformed Democratic nominee Kamala Harris in the state. The three-term senator is making a pitch to working-class voters concerned about cost-of-living issues.

Kansas: Challenging the GOP's lock on Senate seat The Kansas Senate race was not expected to be competitive -- Trump won the state by 16 points in 2024 and Republicans have held both Senate seats in Kansas for nearly a century. Yet even incumbent Republican Sen. Roger Marshall has conceded that it's “quite a close race” this cycle.

Marshall, a medical doctor who served in the House before being elected to the Senate in 2020, has largely supported Trump’s policies during his time in Congress. His opponent, Adam Hamilton, has sought to emphasize Marshall’s ties to the unpopular policies that have created economic challenges for voters.

Hamilton is reverend of the largest United Methodist congregation in the nation. He’s tried to brand himself as an “independent-minded” Democrat but Marshall has said Hamilton is “too woke” to represent the people of Kansas. Maine: Can a 100-day-long campaign unseat an institution?

Longtime Maine Republican Sen. Susan Collins has repeatedly defied the odds, and kept her seat even after being counted out. She’s a moderate Republican who has been more willing than most in her party to break with the president on some issues.

But Democrats think Troy Jackson, a former Maine Senate president and majority leader, could put an end to Collins’ nearly-30-year Senate career.

Jackson was a late entry into the race after Graham Platner, the original nominee, dropped out following sexual assault allegations.

Collins, the chair of the powerful Senate Appropriations Committee, has name recognition and a long record of serving Maine on her side and has tried to highlight her willingness to vote against her party.

Jackson has tried to show Collins failed to when it counted -- notably, Jackson has accused her of "paving the way" for the Supreme Court to overturn Roe v. Wade by casting the deciding vote for Justice Brett Kavanaugh.

Iowa: A surprisingly competitive race Trump has been rallying in Iowa to support Republican Rep. Ashley Hinson’s bid to replace retiring GOP Sen. Joni Ernst in a race that few would be competitive at the beginning of the cycle.

There are no Democrats in Iowa's congressional delegation and Trump won the state by a commanding 13 points in 2024. Iowa has not elected a Democrat to the Senate since 2008.

But rising costs caused by the Iran war have hit Iowa farmers hard. Many see moderate Democratic nominee Josh Turek, a state representative and two-time Paralympics gold medalist in wheelchair basketball, as a formidable candidate against Hinson.