Election Day is once again upon the U.S. and that means there are 435 seats at stake in the U.S. House of Representatives and 33 out of 100 seats up in the U.S. Senate.
Based on history, it should be a good night for Democrats, owing to being the opposition party that just lost the White House. In midterm elections dating back to 1906, the incumbent party that occupied the White House lost seats in the House 27 out of 30 times, or 90 percent of the time, with losses averaging almost 31 seats. In the Senate, comparatively, the incumbent party lost seats 20 out of 30 times, or 66 percent of the time, with losses averaging a bit more than three seats in the Senate.
Just based on the averages, Democrats should easily reclaim the House, where they only need three seats. The Senate could be more difficult, needing four seats to regain the majority, with Vice President J.D. Vance acting as a potential tiebreaker in the event of a 50-50 tie.
So, how to tell what kind of night it might be? One place to look are at-large Congressional districts in non-competitive states.
The reason these at-large districts make for interesting bellwethers is because they are largely uncontested. Nobody’s really spending a great deal of money in them, and they simply let you know what is happening nationally, particular in the House. It’s a test of the mood.
They’re safe seats, and so the question is not whether they were competitive — but what was the margin of victory.
In elections, midterm and presidential, dating back to 2010, in years the Republicans won the popular vote for the U.S. House of Representatives — in 2024, 2022, 2016, 2014 and 2010 — the Democratic candidate averaged 57 percent of the vote in the Delaware at-large Congressional district.
And in years Democrats won the popular vote for the House — 2020, 2018 and 2012 — the Democratic candidate averaged 62.17 percent of the vote in Delaware.
2012 was an interesting year insofar as although Democrats won the popular vote for the House, they didn’t win the majority, which has only happened in modern history three times: 1942, 1996 and 2012. Usually, if you win the popular vote, you win the House, so let’s include that in the base assumption.
2020 was also interesting insofar as Republicans picked up 13 seats in the House as Democrats underperformed with only 50.3 percent of the House popular vote and only winning 222 seats. That year, the Democratic candidate only garnered 57.6 percent of the vote in the Delaware al-large district, compared to 64.4 percent and 64.5 percent in 2012 and 2018.
So, if U.S. Rep. Sarah McBride (D-Del.) is coming in well above 60 percent of the vote, it will likely be a Democratic win in the House of Representatives nationally, but if it’s below 60 percent of the vote, it could prove to be a challenging night for Democrats.
Similar patterns can be found in other at-large Congressional districts depending on which party won the House popular vote.
For example, in Vermont’s at-large Congressional district, when Republicans won the popular vote for the House, excepting 2016 when the Democrat ran unopposed, the Democratic candidate averaged 63.58 percent of the vote. Whereas in years when Democrats won the House popular vote, the Democratic candidate averaged 70 percent of the vote.
But you can do this for red states, too, say South Dakota. In the 2022 midterms, with the Democratic President Joe Biden in office, the Republican candidate garnered 77.4 percent but in 2018 with the Republican President Donald Trump, the GOP candidate only got 60.3 percent of the vote.
On the Senate side, with only one-third of the 100 seats up for grabs, the performance can be a bit more uneven although there are years with critical failures such as the 1958 midterms, when Democrats picked up a record 15 Senate seats amid the 1958 recession.
In the Senate, Republicans will be defending 9 open seats, 7 because of retirements in Wyoming, Oklahoma, North Carolina, Alabama, Iowa, Kentucky and Montana, and 2 because of primaries in Texas and Louisiana. There are also 3 seats where the incumbent was never elected in South Carolina, Ohio and Florida owing to death and moving into the Trump administration. That’s 12 out of 22 Republican Senate seats where the candidate has not faced voters for that seat.
The other 10 Republican seats up for grabs in South Dakota, Tennessee, West Virginia, Nebraska, Mississippi, Maine, Kansas, Idaho, Arkansas and Alaska are incumbents seeking reelection.
We’ll find out very soon which races were safe and which were not. But given critical mass, the lesson of midterms on occasion might be that no seat is safe. Not really. Stay tuned.
Robert Romano is the Executive Director of Americans for Limited Government Foundation.
