One of the most important variables that sticks out in polls is one that few people seem to have noticed: for the first time ever in Gallup polls, Republicans have a Party ID edge over Democrats right before a presidential election. 

"More Americans Identify as Republican Than Democrat. Here’s What That Means for the Election."https://t.co/lzNNZV0k7q

— Josh Kraushaar (@JoshKraushaar) October 9, 2024

NBC polls are showing the same thing, and the effect is not small. It makes a huge difference that the partisan tilt of the electorate has shifted. 

Beneath the headline results in many polls, something unusual has turned up with big implications for politics: More voters are calling themselves Republicans than Democrats, suggesting that the GOP has its first durable lead in party identification in more than three decades.

The development gives former President Donald Trump an important structural advantage in the November election. But other factors could prove more important to the outcome. Democratic Vice President Kamala Harris still leads narrowly in many polls, in some cases because she does well with independent voters.

Bill McInturff, a GOP pollster who works on NBC News surveys, first noticed in May that more voters were calling themselves Republicans. “Wow, the biggest deal in polling is when lines cross, and for the first time in decades, Republicans now have the national edge on party ID,’’ he wrote. He called the development “the underrecognized game-changer for 2024.’’

In combined NBC polls this year, Republicans lead by 2 percentage points over Democrats, 42% to 40%, when voters were asked which party they identified with. That compares with Democratic leads of 6 points in 2020, 7 points in 2016 and 9 points in 2012.

“Republicans being 5 to 9 points down on party identification—that is like running uphill,’’ McInturff said. “We don’t know the election’s outcome, but we know Republicans have a better shot at doing well if party ID is functionally tied, with perhaps the smallest tilt toward Republicans.’’

Gallup also found more voters identifying as Republican than Democratic, by 3 points in its July-to-September surveys. It was the first time that the GOP had an advantage in the third quarter before a presidential election in Gallup surveys dating to 1992.

That swing in voter party preference is HUGE. Republicans are doing 8 points better in party ID than in 2020 and 9 points better than in 2016. Poll results are not determined by raw random samples these days because the data collection is not done randomly. It can't be because segments of the population are more or less likely to answer polls or be accessible to pollsters. 

Every pollster has a "special sauce" they use to model the electorate, including weighting party identification. Honest pollsters aren't cooking the books so much as trying to reshape their data to fit their model of what a truly random sample would look like. 

Of course, if the electorate doesn't look like the model, the poll will be wrong. This isn't a "margin of error," which is calculated by the number of data points. It is a fundamental problem because the data is not randomly collected. MOEs assume random samples. 

That's a too long explanation for a simple problem: if Gallup and NBC are seeing a genuine shift in party ID, most polls will be wrong unless the correct for that shift, as well as the "shy" Trump voter.

The polls in the last two presidential elections were horribly off--well outside the margin of error--because the model of the electorate was wrong. Take a look at the polling from the last two cycles on this day from RealClearPolitics:

This Day In History: October 9, 2020: Biden +9.7 | October 9, 2016: Clinton +4.6

In their RCP poll average for today they have Harris up by 2. That is almost 8 points lower than Biden's average in 2020. 

This race is TIGHT: within 2 points in all 7 critical battlegrounds. Harris barely wins if the result matches the polls.

But Trump crushes Harris & wins all the key states with a 2020 like poll miss. Harris, though, crushes Trump & wins all of them with a 2022 like poll miss. pic.twitter.com/b3ZJlbRI0w

— (((Harry Enten))) (@ForecasterEnten) September 20, 2024

Harry Enten of CNN does excellent poll analyses, bringing the complex down to the simple. He has done several segments about the difficulties of understanding polling and how to read them. 

Why 2024 is way too close to call: The avg. state polling miss is 3.4 pts since 1972. All swing states are within that.

The true margin of error of state poll avgs. is way bigger (+/- 9.4 pts).

Anything from a Trump 300+ electoral vote win to Harris doing the same is possible. pic.twitter.com/ViMI4aXyCB

— (((Harry Enten))) (@ForecasterEnten) October 8, 2024

Some pollsters clearly cook the books, misrepresenting the electorate. But every pollster has to contend with the fact that poll data is not actually random, as necessary to get reliable polls. The statistics can be dead on, but the data has to be shaped before the analysis is done. 

Who is a "likely voter?" "How many Republicans, Democrats, and Independents are there in real life?" "How do we collect the data since each demographic prefers to use different communication tools?" Dishonest pollsters can make the data say almost anything, and honest pollsters still have to make educated guesses to make the data make sense. 

Of course, Democrats should be nervous.
Of course, Republicans should be nervous.

This is race has been consistently tight to a historic degree... It could break either way... or it could be as close in the vote count as the polls indicate now. pic.twitter.com/mTJ02639PN

— (((Harry Enten))) (@ForecasterEnten) October 9, 2024

Political consultants know the strengths and weaknesses of polls and are much more demanding than media outlets because they use the data not to generate interest in the story but to actually win elections. Horserace polls are entertainment for political junkies; internal campaign polls are for directing strategy. 

"I just saw some new private polling that's very robust. Private polling," says @MarkHalperin. Kamala Harris "is in a lot of trouble … In the conversations I'm having with Trump people and Democrats with data, they are extremely bullish on Trump's chances in the last 48 hours.… pic.twitter.com/KF3tSM2sLo

— 2WAY (@2waytvapp) October 9, 2024

That's why you have seen a shift in Harris' strategy. Her internals clearly told her that what she was doing was not working. Those polls could be wrong, too, for the same reasons, of course, but the pollsters tend to be much more stringent about their methods because they need repeat clients who demand a lot more than the news outlets, who want exciting results, or results that say what they want them to. 

The shift from Democrat to Republican preference is an indicator that the electorate has changed. It doesn't guarantee a Trump win since Independents ultimately choose the victor. But it does say something about the mood of the electorate. They are sour on Democrats. 

With Kamala tying herself to Biden more publicly, this could have a major effect. Republicans sure think so, given how they have jumped on Harris' saying she would do everything as Biden has. 

🚨 NEW AD pic.twitter.com/QAtPWIme91

— Trump War Room (@TrumpWarRoom) October 9, 2024

The Harris campaign is scared, and they should be. I am not PREDICTING a loss, but I think a Trump victory--if trends continue--is more likely than not. 

This is insane. Trump is polling nearly double digits better in Pennsylvania than both Biden 2020 and Clinton 2016 at this point in the race. WOW. pic.twitter.com/ChZLF0bL0l

— Eric Daugherty (@EricLDaugh) October 9, 2024

I suspect the public pollsters are, for the most part, trying to get reasonably accurate results, but if there is an error half as bad as the last two election cycle you should expect that Trump wins pretty easily in the electoral college. He may even have a shot at the popular vote. 

Well see.