The 2022 Midterms were exceptionally successful for Democrats as the party expanded their majority in the US Senate and only lost 9 seats in the US House. Democrats also won nearly every competitive gubernatorial election (including races in five states Donald Trump won in 2016—Kansas, Arizona, Michigan, Wisconsin, and Pennsylvania) and flipped state legislative chambers in Minnesota, Pennsylvania, and Michigan. In the context of historical precedent, where the incumbent president’s party generally suffers heavy losses in his inaugural midterm, the result is even more impressive for Democrats. So, how did Democrats do it?
Republicans Easily Won the National US House Popular Vote
Although Republicans suffered extremely underwhelming results this midterm, they still enjoyed a decent result in the US House national popular vote. In 2020, President Joe Biden won the Presidential popular vote over Trump by 4.4%. Historically, a new President’s political party generally struggles in their first midterm after assuming office. Although Republicans slightly underperformed pre-election expectations (FiveThirtyEight predicted Republican US House nominees would win nationally by a 3.3% margin on the evening before Election Day), they still won the popular vote by 2.1%. As Republicans pursue a policy agenda significantly to the right of the median American and willingly make “unpopular” policy decisions on important issues, political analysts may need to get used to the idea that America is (temporarily) a blue nation. Blue Waves may be massive, and Red Waves stunted, as long as Republicans continue their current electoral strategy. Republicans haven’t won the Presidential popular vote in 19 years, and the party shows no signs of changing its electoral strategy. As partisanship becomes more powerful and ticket-splitting decreases, a 6.5% swing into a favorable national environment is at least a solid result and should not have resulted in electoral failure for the GOP.
Republicans Drastically Underperformed in Both the House and Senate
Unfortunately for the GOP, Republican candidates could not efficiently convert this favorable national political environment into success in the US House and Senate. I’ve already written extensively about how the US House was surprisingly structurally biased toward Democrats, even though the 2021/2022 redistricting cycle went well for Republicans. With increasing gains for the party in majority-minority communities and losses in the suburbs, Republicans are no longer distributing their voters as efficiently for US House success as during the 2010s. While this development is serious (the GOP may not hold a well-functioning majority in the House this cycle), it is merely unlucky and mostly out of the party’s control. Republicans should be more actively dismayed by their defeat in the US Senate. While Republicans hoped to gain seats in the US Senate and flip control of the chamber, Democrats swept competitive races in Nevada, Arizona, Georgia, and Pennsylvania to widen their Senate majority to 51-49. Given that Trump lost these states by an average of ~1% in 2020, it is incredibly improbable that Republicans managed to lose all four of these seats in a ~7% better national political environment just two years later. Given that Republicans won the national popular vote by 2.1%, a fundamental model expects the GOP to have won the Senate races in Arizona, Georgia, and Pennsylvania, enough for a 52-48 majority. In reality, Republicans drastically underperformed expectations and managed to allow control of the Senate to stay in Democratic hands.
Regional Red Waves: Florida, New York, and California
While Republicans enjoyed a generally favorable national political environment (R+2), the party failed to win races in traditional “swing” states. There is certainly some evidence (outlined below) that Republican Senate candidates were exceptionally weak, and “generic Republicans” would have been significantly more successful than the array of Trump-backed candidates the party actually nominated. But another, more important factor explains Republicans’ failures to win battleground Senate races. While the national political environment is generally very consistent across the nation in Presidential elections, the complex set of salient issues during this midterm led to asymmetric political environments around the country in 2022. While Republicans enjoyed “Red Wave” environments in Florida, New York, and California (coincidentally the three of the four most populous states), the rest of the nation actually trended left from the 2020 Presidential Election to the 2022 midterms. Republicans suffered uninspiring results in most of America, not just in swing states with Senate races. While Republicans certainly enjoyed watching Ron DeSantis’ blowout victory unfold in Florida and Kathy Hochul’s close call in New York, these results did nothing for GOP Senate hopes. Again, this failure is not controllable—it’s just bad luck for the GOP that their strengths were organized so suboptimally this election cycle—but it is about time it happened. The GOP has long relied on structural advantages (the team at FiveThirtyEight published a wonderful piece on this) to fuel electoral success, and eventually, this good fortune will start to run out.
McConnell Was Right: Poor Candidate Quality Fuels Senate Hardships for GOP
Republican Senate Leader Mitch McConnell downplayed Republican’s outlook in the chamber in the months leading up to November, noting the importance of “candidate quality” and implying disappointment in the summer’s primary results for the party. The GOP nominated three political newcomers endorsed by Trump—Mehmet Oz (PA), Blake Masters (AZ), and Herschel Walker (GA)—all of whom ultimately underperformed fundamentals by a wide margin in November. While analysts speculated throughout the fall about the potential weaknesses of this trio, there is also hard evidence that it’s hard to for political newcomers to jump straight to the Senate. In the end, Masters underperformed GOP US House nominees in Arizona by 14 points, Oz underperformed House nominees by 9, and Walker underperformed House nominees by 7. McConnell blamed these shortcomings on Trump after the failed election, bemoaning the former President’s impact on GOP Senate primaries and his lack of interest in candidate quality.
Edit: Updated to reflect the correct state population rankings.
Author’s Note: As is the norm in this type of analysis, all recent and historical statistics regarding the “US House National Popular Vote” have been adjusted for uncontested seats. For example, the article notes that “Republicans won the  popular vote by 2.1%,” despite the raw number being more like 2.8%. This is because Republicans only left 3 seats uncontested, while Democrats left 13 seats uncontested. Candidates from left-wing minor parties challenging unopposed Democrats also artificially deflate their popular vote total. All statistics, even from external sources, have also been altered by this 0.7% adjustment to increase clarity for the reader.