Fox News Power Rankings for the Senate. (Fox News)
In Ohio, Democratic incumbent Sen. Sherrod Brown faces a challenge from Republican Bernie Moreno in what's projected to be the most expensive race outside the presidential contest, according to the Marion Star, given the outcome could determine which party controls the upper chamber of Congress.
Former President Trump endorsed Moreno earlier this year in the Senate Republican primary.
Moreno briefly ran for Senate in 2022 to replace retiring Republican Sen. Rob Portman, but JD Vance, now Trump's vice presidential running mate, won the nomination and later the general election.
Trump carried Ohio by eight points in both the 2016 and 2020 elections.
In Pennsylvania, considered a pivotal battleground in the presidential race, incumbent Democratic Sen. Bob Casey is up against Republican challenger Dave McCormick.
McCormick, a West Point graduate who served in Iraq in the 82nd Airborne Division and later as the CEO of the world's largest hedge fund, took the stage ahead of Trump at the Republican presidential nominee's last rally in the state Monday night. McCormick told a Pittsburgh crowd that his opponent, Casey, was a "career politician" with more than 30 years in office, before also attacking Vice President Harris.
Senate candidate Tim Sheehy speaks during a rally for former President Donald Trump at Montana State University on Aug. 9, 2024, in Bozeman, Montana. (Michael Ciaglo/Getty Images)
Republicans have pinned their hopes on Tim Sheehy, a former U.S. Navy SEAL and founder of an aerial firefighting company. Sheehy, 38, had early backing from party leaders, including Trump, clearing the political newcomer's path to win the June primary.
This is the first time Tester’s name appears on the same ballot as Trump, who won Montana by wide margins in 2016 and 2020.
A Sheehy victory would seal Republican Party dominance across the five-state Northern Plains region: Tester entered office as one of six Democratic senators in the largely rural swath of American heartland that also includes Wyoming, Nebraska, North Dakota and South Dakota. He's now the only one.
The lawmaker also is the sole remaining Democrat to hold statewide office in Montana.
Two-term Republican Sen. Deb Fischer faces her strongest re-election challenge yet Tuesday as she takes Dan Osborn, a former labor union boss who eschewed both major political parties to run as an independent while painting himself as a working class champion.
The state GOP, whose leadership is loyal to Trump, endorsed primary challengers to all five of the Republicans who represent Nebraska in Congress, including Fischer.
Democratic Maryland Senate candidate Angela Alsobrooks in Chicago, Aug. 20, 2024, and Republican opponent, former Maryland Gov. Larry Hogan in Annapolis, on Aug. 27, 2024. (AP Photo Erin Hooley, left; and AP Photo Stephanie Scarbrough, File)
The stakes are unusually high for a Maryland race that includes a Republican who won significant Democratic support in his 2014 and 2018 gubernatorial victories. Hogan is only the second Republican in Maryland history to be re-elected governor.
Abortion has been a major issue in a campaign taking place at the same time that voters in Maryland and eight other states will be considering a constitutional amendment to enshrine abortion rights in the state constitution, after the U.S. Supreme Court struck down Roe v. Wade in 2022.
Alsobrooks has prioritized abortion rights in her campaign, saying one of her first actions as a senator would be to sponsor legislation to codify Roe into federal law. Hogan also says he would co-sponsor such legislation, but Alsobrooks is quick to point to a Hogan veto when he was governor of a bill in Maryland to expand abortion access in 2022.
In a presidential swing state, Democratic Sen. Jacky Rosen – a former computer programmer and synagogue president – is facing a challenge from Republican Sam Brown, a retired Army captain whose face is still scarred from injuries he suffered in Afghanistan.
The first-term Rosen has outspent Brown by more than 3-1 in the contest, positioning herself as a nonideological senator who delivers for her home state on issues like broadband internet access and a high-speed rail connection with Southern California.
Brown, who was awarded the Purple Heart, has campaigned on his biography and the state's cost-of-living crisis, particularly acute in working-class Nevada. He's had trouble gaining traction, though a last-minute infusion of GOP money in late October came as Republicans, cheered by strong turnout for their party in early voting, hoped Brown could upend expectations in the race.
Trump endorsed Brown in the state's primary.
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Brown in 2008 was grievously wounded by an improvised explosive device during a Taliban ambush of his unit in southern Afghanistan. He left the army in 2011 after 30 surgeries and years of recovery, founding a business to help veterans get medical care. Brown's face remains seriously scarred and has become central to his campaign ads.
The Associated Press contributed to this report.
Danielle Wallace is a breaking news and politics reporter at Fox News Digital. Story tips can be sent to danielle.wallace@fox.com and on X: @danimwallace.
https://www.foxnews.com/politics/9-competitive-senate-races-watch-election-night