Both parties had something to celebrate after Tuesday’s midterm elections, depending on where they looked. But that split outcome — with Democrats winning the House, and Republicans gaining seats in the Senate — underscores the extent to which opinions about President Donald Trump shape today’s politics.

Republicans largely prevailed at the Senate level because they were running in red states where President Donald Trump performed well in 2016. The House saw the opposite outcome, but the reason was the same. Republicans largely struggled because they were running in places where Trump was unpopular.

Republicans at the House level and Democrats at the Senate level argued that they had incumbents who could withstand a wave — lawmakers with independent brands and bipartisan appeal. But many of those incumbents lost.

Yes, candidates matter. But on Tuesday, opinions about Trump, which often translated to party preference, may have mattered more.

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Democrats dominate

Just look at the House, where Democrats always knew the low-hanging fruit was going to be GOP-held seats that Hillary Clinton won in 2016. These were well-educated districts that often backed Republicans for Congress but wanted a check on Trump this year.

Democrats successfully knocked off GOP incumbents who were known for over-performing the top of the ticket, some of who had even brandished moderate credentials in Congress.

Just three of the 25 GOP incumbents running in districts Clinton won in 2016 have so far prevailed.

Incumbents such as Virginia’s Barbara Comstock, Colorado’s Mike Coffman, Minnesota’s Erik Paulsen, Kansas’ Kevin Yoder, New Jersey’s Leonard Lance and Illinois’ Peter Roskam all fell Tuesday night. It didn’t matter how much they tried to distance themselves from the president or the party. Their constituents wanted a check on the president, and that meant voting Democratic.

Minnesota’s 3rd District voters had previously split their tickets, giving Paulsen a fifth term in 2016 by a 14-point margin at the same time they were electing Clinton by 9 points. But this time — Paulsen’s first re-election with a Republican in the White House — was different. Well-educated voters in the Twin Cities suburbs chose Democrat Dean Phillips.

Likewise in New Jersey’s 7th District, GOP Rep. Leonard Lance voted against the Republican tax and health care legislation. But in an affluent district that Clinton narrowly carried, that wasn’t enough to save him. Voters here chose Democrat Tom Malinowski, throwing out a five-term Republican known for his moderation and civility.

Similarly in Florida’s 26th District, Republicans were banking on GOP Rep. Carlos Curbelo once again defying his party’s preference for a Democrat at the top of the ticket. (He overperformed Trump by 12 points in 2016.) He touted his willingness to stand up to his own party, whether on climate change, gun control or immigration. But he fell to Democrat Debbie Mucarsel-Powell on Tuesday.

Many of these Republicans have an unfavorable national environment to thank for their loss. That’s not to say their challengers were insignificant. Democrats had to field viable recruits to harness the anti-Trump energy. And many first-time candidates proved to be impressive fundraisers who ran strong campaigns.

Early on in 2018, some Republicans conceded that a strong Democratic recruit, regardless of who it was, would doom their incumbents in unfavorable districts. Congressional Leadership Fund, for example, never invested in Virginia’s 10th District — not because Comstock wasn’t a good incumbent or an ally of leadership, but because the GOP super PAC didn’t see a path to victory in a district Clinton carried by 10 points.

Even in closely divided districts that Trump won, the national environment helped propel Democrats to victory. Take New York’s 19th District, which GOP Rep. John J. Faso described as a “microcosm of the country.” Voters here backed former President Barack Obama twice and flipped to Trump in 2016.

Faso ended up losing to Democratic lawyer Antonio Delgado by 2 points. Democrats in the Upstate New York district have been energized for most of the cycle, holding weekly protests outside Faso’s office since early 2017.

Few Senate surprises

While Democrats were making gains in the House, Republicans were securing control of the Senate. And although these outcomes led to divided government, they happened for the same reason. As with key House races, party loyalty overwhelmed sitting senators who previously held cross-party appeal.

Democrats acknowledged from the start of the cycle that the chamber would be difficult to flip. But by leaning into their personal brands, it looked like their incumbents might be able to survive in states Trump won. 

That began to change this fall. The fight over Supreme Court Justice Brett M. Kavanaugh and Trump’s repeated visits to red states nationalized the Senate contests. In the end, they reverted to their partisan lean — with the exception of West Virginia and Montana. Democratic incumbents held on there, albeit by slim margins.

In North Dakota, Sen. Heidi Heitkamp, the last remaining Democrat in statewide office, lost to GOP Rep. Kevin Cramer by 11 points. In Missouri, where the race stayed close for most of the cycle, Democratic Sen. Claire McCaskill fell to state GOP Attorney General Josh Hawley by 6 points. In Indiana, Republicans privately grumbled that GOP nominee Mike Braun was running a lackluster campaign and it looked like Democratic incumbent Joe Donnelly’s bipartisan appeal might carry the day. But in the end, Braun defeated the incumbent by 8 points.

Democratic hopes were dashed early Tuesday night when they lost two potential pickup opportunities in Tennessee and Texas. Former Democratic Gov. Phil Bredesen, the last Democrat elected statewide in Tennessee, was likely the only Democrat who could have made the Senate race competitive, but he couldn’t overcome GOP Rep. Marsha Blackburn in a heavily Republican state.

It’s possible that Texas is shifting further to the left, as Democrats hope, since Texas GOP Sen. Ted Cruz defeated Democratic Rep. Beto O’Rourke by just 3 points. But O’Rourke’s millions, large crowds, and the coattails that helped flip some House seats still couldn’t translate into a statewide win, underscoring how tough it is to overcome partisan makeup in a polarized environment.

Nevada, though closely divided politically, cemented its status as a swing state with Democratic Rep. Jacky Rosen unseating Republican Dean Heller. Again, this wasn’t too surprising given that Heller was the only GOP incumbent up for re-election in a state Clinton carried in 2016.

The exceptions

Some candidates from both parties defied the midterm trend in their districts or states on Tuesday.

Democratic Sen. Joe Manchin III of West Virginia defeated state Attorney General Patrick Morrisey, although the margin was narrower than some polling had predicted. Still, it was a noteworthy victory in a state that backed Trump by 42 points. Likewise in Montana, Democratic Sen. Jon Tester barely defeated GOP state Auditor Matt Rosendale, but Trump carried the state by 20 points two years ago.

On the House side, two Republicans in Clinton districts survived due to a combination of incumbent strength and issues with Democratic challengers.

In New York’s 24th District, Democrat Dana Balter won a surprise primary victory but went on to lose to GOP Rep. John Katko by 6 points. Balter, who supported “Medicare-for-All” legislation, might have proved too liberal for a district that only narrowly backed Clinton.

GOP Rep. Brian Fitzpatrick prevailed in Pennsylvania’s 1st District in the Philadelphia suburbs against wealthy Democrat Scott Wallace, who faced criticism for recently moving back to the district. Fitzpatrick was also the rare Republican who had union support as well as the endorsement of Giffords PAC, which backs candidates who support gun control.

Republicans largely won competitive districts where they were favored. But two of the biggest upsets of the night came in two GOP districts, where demographic shifts or local issues could have been at play.  

In Oklahoma’s 5th District, Kendra Horn defeated GOP Rep. Steve Russell in a race that wasn’t on anyone’s radar. Trump won the seat by 13 points in 2016. Horn’s campaign argued that the district has been changing, citing earlier Democratic victories in special elections at the state level.

Democrat Joe Cunningham defeated Republican Katie Arrington in South Carolina’s 1st District, which opened after Arrington defeated Rep. Mark Sanford in the GOP primary. Arrington’s professed support for lifting the ban on offshore drilling during the primary may have swayed this race, where national Republicans made a late investment in the final week.