Blue wave or big polling error? Here’s why it’s hard to tell

A major problem with predicting who will win the Senate in next Tuesday’s midterm elections is that the signs of a blue wave and a polling miss look alike.Democrats currently lead in nearly all the most competitive Senate races a week out from the election, with Republicans clinging to leads of less than 1 point in Kansas and Iowa. That’s a sign of a blue wave.But Democrats don’t safely lead outside the margin of error in these races, except for North Carolina and Georgia (which are arguably no longer competitive), both purple states. The path to a Senate majority mostly runs through red states, not purple ones. Red-state Senate races have seen some of the biggest polling misses in recent years, with Republicans winning comfortably on Election Day after the polls looked tight.Two of the bluest states with competitive Senate races this year are Maine, where Sen. Susan Collins (R-ME) won by nearly 9 points six years ago despite trailing in nearly every poll (her numbers actually look better this year), and Michigan, where there was a huge polling miss (as well as some fake polls) in the Democratic primary. President Donald Trump carried Michigan in two of the last three presidential elections and has won an electoral vote from Maine’s 2nd Congressional District in each of the last three.These facts don’t prove that the general election polls are going to be wrong. But they arouse suspicions, and few of the Democratic Senate candidates in this seemingly blue year have leads that are large enough to withstand much of a polling error.But why are red-state polls sometimes wrong? One reason is that they underestimate the rural vote. Another is that the undecided voters tend to lean Republican and enough of them come home on Election Day to put the GOP candidate over the top.Former Democratic strategist Evan Barker has predicted that Texas Democratic Senate candidate James Talarico will lose despite his small but steady polling lead because of a lack of engagement with rural voters. One elections expert cited rural polling nonresponse as a major problem in Iowa.The Republican-leaning undecideds are why Trump and Vice President JD Vance are campaigning in so many red states where the Senate candidates are underperforming. The theory is that if Republicans turn out and vote for their party’s candidates, they will be able to win in predominantly Republican states.Sounds logical. But what if this is the year that wavering Republicans don’t end up supporting their party in sufficient numbers or the absence of rural voters from the polls carries over to voting?Some Republicans have raised this concern. “We’re having problems just getting Republican voters to respond to polls,” a GOP pollster told Axios. “At what point do we think these guys aren’t showing up at the actual polls on Election Day?”One problem for Republicans is that more and higher-quality polling than exists in most of these Senate races supports the idea of a bad national environment for their party. Trump’s job approval rating is at 40% or lower in most polls. Those numbers are worse when it comes to approving how he is handling specific issues, such as inflation, the economy, and Iran. Democrats are favored in the generic congressional ballot by anywhere from 5 to 11 points.The hope for Republicans for the past year, following a series of Democratic wins last November that were often bigger than the polls predicted, was that the map would protect them from the bad national conditions that often plague the party in power during midterm elections even in the absence of high prices or unpopular wars.Before this year’s redistricting wars, 80% of House Republicans represented districts that Trump carried by at least 12.5 points and 61% represented districts that had gone for Trump by at least 20 points. In the blue wave election of 2018 during Trump’s first term, Republicans lost only six House seats in the former category and zero in the latter.Similarly, most of the top Senate races this year are taking place in states Trump carried in 2024. Republicans actually had a net gain of two Senate seats in the 2018 midterm elections because of races in red states. That’s why Trump is urging Republicans to behave as if he is on the ballot himself this year, as Democrats surely will do.But Trump is also the reason these Republicans are in trouble. Democratic Senate candidates are tied or ahead in states Trump won by double digits just two years ago. And House Republicans are seeing troubling signs in their internal polls in districts that weren’t previously thought to be competitive.Unlike in 2022 and 2024, Republicans aren’t seeing anything markedly different or better in their private data than in the public polls. That also could either mean a blue wave, or that the polling bias is systemic.OBAMA’S AWKWARD PLACE IN EL SAYED’S DEMOCRATIC PARTYIf traditional Republicans who have never liked Trump but have in the past held their noses and rural voters upset by tariffs, high fuel prices, and data centers are the keys to this election, maybe they don’t save the GOP this time.We won’t know for sure whether it’s a blue wave or if the pollsters blew it until after the election, since the signs of both are so hard to tell apart.