Florida: Longtime incumbent Senator Bill Nelson is facing a tough reelection campaign, especially now that Governor Rick Scott has officially entered the race. Recent polls have shown Nelson clinging to a single-digit lead over Scott in a head-to-head matchup. Donald Trump’s popularity may loom large over this competitive state, because Scott is one of President Trump’s most ardent supporters, backing him early on the presidential primary. Scott’s PAC eventually raised $20 million on behalf of the President in 2016. This will be one of the biggest races to watch in November.
Indiana: Senator Joe Donnelly is perhaps the most vulnerable Democrat up for reelection in 2018. He won a close race in 2012 over Tea Party candidate Richard Mourdock, who himself unseated longtime Republican Senator Dick Lugar in a primary that represented the height of the fringe group’s influence. Lugar’s loss created the pickup opportunity for the Democrats, which was still a close race despite repeated inflammatory comments by Mourdock throughout the campaign. Tuesday’s Republican primary was decided after wealthy businessman Mike Braun won a three-way race with Congressman Todd Rokita and Congressman Luke Messer. The contest was nasty, as each candidate attempted to align himself closest with Donald Trump. There is some logic to this tactic, as Donald Trump carried the state by 19.1 points and remains popular. This campaign will be a true test of Donnelly’s local appeal.
Missouri: We expect Senator Claire McCaskill to face a very difficult road to reelection as Donald Trump carried the state by more than 18 points in 2016. Her effort has been helped by controversy surrounding Republican Attorney General Josh Hawley—widely seen as the strongest Republican challenger—who recently implied that feminism and the “sexual revolution” are to blame for child sex trafficking. His missteps are reminiscent of McCaskill’s 2012 opponent Todd Akin, who torpedoed his own campaign with similarly controversial statements.
Hawley’s repugnant missteps and his connection to supporters of former Alabama Senate candidate Roy Moore will be problematic. Further, McCaskill’s fundraising prowess gives hope that she may yet win again. Hawley faces ten primary challengers, but is widely expected to emerge as the candidate. President Trump remains popular in Missouri, with approval ratings in the state approaching 50 percent, so McCaskill’s reelection is by no means secure. She continues to benefit from political good fortune, while deftly navigating the Senate as a moderate.
In addition to Hawley’s missteps, the Republican Party is dealing with another statewide problem in the person of Governor Eric Greitens whose extramarital affair and other legal troubles threatens to pull the party down with him.
Montana: Democratic Senator Jon Tester has consistently opposed Donald Trump’s deplorable agenda, despite Trump winning Montana by more than 20 points. Senator Tester bucked the trend among vulnerable Democrats by voting against the temporary funding measure that ended the brief government shutdown in January, and he voted against the confirmation of Supreme Court Justice Neil Gorsuch last year.
Senator Tester has never won more than 50 percent of the votes cast in his previous campaigns, benefiting from a Libertarian candidate in 2012 who captured more than six percent of the vote. Despite two close elections, Senator Tester boasts a 53 percent approval rating among Montana voters, giving him reason to be confident. Republicans have experienced some recruiting setbacks for this race, but their field remains crowded. State Auditor Matt Rosendale appears to be the NRSC’s preferred candidate, while also enjoying the support of the Steve Bannon wing of the GOP. His main challengers in the June primary appear to be businessman and Air Force veteran Troy Downing, who has aggressively sought Donald Trump’s support, as well as from former Judge Russell Fagg.
Tester recently made news by leading the charge against Dr. Rony Jackson, President Trump’s brief nominee to head the Department of Veterans’ Affairs.
North Dakota: Democratic Senator Heidi Heitkamp is one of the most vulnerable incumbents this year. Republican Congressman Kevin Cramer joins State Senator Tom Campbell in the contest for their party’s nomination. North Dakota’s obvious Republican slant assures that Heitkamp will face a tough challenge regardless of her opponent. In September 2017 a poll showed that 44 percent of North Dakota voters “wanted someone new” representing them in the Senate as opposed to 42 percent favoring Heitkamp. However, Heitkamp’s cash advantage should help balance the playing field. As of her last filing, Heitkamp has raised more than $6 million toward her reelection.
Ohio: Senator Sherrod Brown is the only Democrat holding statewide office in Ohio. The state swung toward Republicans in 2016, following President Obama’s 3-point victory in 2012. Donald Trump beat Hillary Clinton by 8 points. Congressman Jim Renacci handily won Tuesday’s primary with 47.4% of the vote. Senator Brown remains popular in his state, which gives us confidence that he will win a close election.
West Virginia: Like Claire McCaskill in Missouri, Senator Joe Manchin has endured West Virginia’s transition from a competitive bellwether state to a Republican stronghold. The 2018 primary featured a crowded Republican field. State Attorney General Patrick Morrisey beat out both Congressman Evan Jenkins and convicted coal company CEO Don Blankenship in Tuesday’s primary and will align himself closely with President Trump, who won the state by a whopping 42 points in 2016. Despite these political realities, a poll in 2017 found that Senator Manchin—a former governor—remains more popular than President Trump.
Wisconsin: Senator Tammy Baldwin has already weathered $3.1 million of outside spending by Republican groups since late 2017. Wisconsin has been trending Republican in recent elections and is home to a strong Republican mobilization machine, built in part by Governor Scott Walker, who is also on the ballot in November. Businessman Kevin Nicholson has moved to the front of the pack of potential challengers, raising more than $1 million for his campaign, but other challengers such as State Senator Leah Vukmir remain in the contest. Senator Baldwin’s approval ratings are cause for more concern, as a recent Morning Consult poll showed that only 40 percent of voters approve of her job as Senator.