Democrats Gained These Voters in 2018, and Biden Needs to Keep Them Now

Welcome to Poll Watch, our weekly look at polling data and survey research on the candidates, voters and issues that will shape the 2020 election.

Two years ago, a flood of anti-Trump sentiment helped flip the House of Representatives blue, with Democratic candidates winning more votes than Republicans by nearly 10 percentage points nationwide — a record margin for a party that had been in the minority.

Because the 2018 election was largely seen as a referendum on President Trump, Democratic strategists are looking to carry those gains forward. Indeed, national and swing-state polls continue to show Joseph R. Biden Jr. with a steady lead — particularly in the suburban areas where Democrats made some of their biggest gains in the midterms.

But Mr. Biden may not be able to count on the same level of support that Democratic candidates received in 2018. Some of the groups that swung hardest in Democrats’ direction in 2016 have been slow to warm to Mr. Biden. Compared with an authoritative study of the 2018 midterm electorate released this week by the Pew Research Center, recent polls show the party’s presidential nominee lagging behind the rates at which certain key demographics broke for the Democrats two years ago.

To conduct the study, Pew used its American Trends Panel, which tracks a nationally representative sample of Americans and allows researchers to re-contact the same voters over time. Because of its large sample size and because it used a method called voter validation — checking panelists’ responses against publicly available voter files to confirm that they participated when they said they did — Pew’s study is considered more reliable than the national exit polls, which are conducted quickly on the day of the election and undergo minimal adjustments afterward.

Midterm elections after a new president has taken office always tend to be tough for the president’s party. Yet midterm voters also tend to skew slightly more affluent and conservative than general-election voters. So the surge in Democratic votes across the board, particularly among key groups, appears to tee up Mr. Biden for a strong showing.

Latinos, white suburbanites and young voters swung especially hard in Democrats’ favor in 2018, as the Pew study reflected, sometimes even more starkly than the exit polls. Here’s a look at what the Pew study tells us about those groups, and at where things stand now.

Young voters

Youth enthusiasm and participation ran low in the 2016 general election, but voters under 30 grew heavily involved in 2018 — doubling their participation rate from the previous midterms, according to an analysis by the United States Elections Project at the University of Florida. No other age group jumped by as much.

In 2016, most young voters saw neither candidate in a positive light, and 14 percent of them expressed their displeasure by voting third party, a far higher number than for older voters. But as they surged to the polls in 2018, those under 30 picked Democratic House candidates by an enormous 49-point margin. (That’s way more than the 35-point advantage that national exit polls from 2018 had indicated.)

Scott Keeter, a senior survey adviser at Pew who helped assemble the report, noted that people under 30 accounted for more than one-third of 2018 voters who had not cast ballots in 2016. “That’s a fairly striking figure,” he said. “And they were already a good group for Hillary Clinton, but they became even more Democratic in 2018.”

Yet Mr. Biden is not particularly popular among young people: His favorability rating is five points in the negative among likely voters under 35, according to the latest Quinnipiac University poll. Still, young voters appear to be even less fond of Mr. Trump — and uninterested in sitting out another presidential election.

Mr. Biden leads Mr. Trump by 63 to 27 percent among voters under 35, according to Quinnipiac; that’s better than Mrs. Clinton’s 58-28 margin among the youngest voters in 2016, according to Pew, and it suggests that those who didn’t vote or who cast third-party ballots in 2016 may be wary of doing so again.

Hispanic voters

Hispanic turnout two years ago jumped by 74 percent from the 2014 midterms — more than for any other major racial or ethnic group — according to voting data compiled by the Elections Project. (The growth rate for Black and white voters was about half that.) These voters favored Democrats by a whopping 47 points in 2018, with just a quarter of Hispanic voters casting ballots for Republicans, the Pew study shows. That was a nine-point gain on Mrs. Clinton’s margin in 2016.

Mr. Biden is up on Mr. Trump by anywhere from 20 to 32 points among Hispanic voters nationwide, according to recent polls. That is considerably weaker than Mrs. Clinton’s advantage, and far below the Democrats’ wider lead in 2018.

Partly because the Hispanic population is so diverse — with regard to nation of origin, racial identity and political thought, among much else — and because phone surveys rarely have a Hispanic sample of much more than 100 people, this group can be hard to accurately poll. Pollsters have long considered exit polling of Hispanic voters to be notably problematic.

That is part of what is so valuable about the Pew report, which affirms, using validated voters, how Hispanic voters actually cast ballots — though it doesn’t break down the Hispanic population into more specific demographic categories.

“There’s all sorts of signals coming from the polling world,” Mr. Keeter said, “that make it hard to know how enthusiastic the Latino vote is for Biden and ultimately how much they’re going to turn out for him.”

Suburban voters

Suburban voters were crucial to Democratic victories in many House districts that flipped from red to blue in 2018, and Pew’s results reflected that trend nationwide. While the suburbs over all broke just barely for Mr. Trump in 2016, these increasingly diverse areas of the country swung Democratic by seven points in 2018, Pew found.

Among white suburbanites in particular there was still a slight Republican tilt in the midterms, but these voters chose Democratic candidates 47 percent of the time, according to Pew. That was up from the 38 percent who voted for Mrs. Clinton.

This is one area in which Mr. Biden is well positioned to carry the gains of 2018 forward — and even exceed them. An NPR/PBS NewsHour/Marist College poll last month showed Mr. Biden winning in the suburbs by a whopping 25 points. A separate Marist poll this week of Pennsylvania found Mr. Biden leading in the suburbs by 19 points

Who got more involved in 2018

In a sign of just how heavily the anti-Trump winds were blowing in the midterms, when you look specifically at new voters and 2016 abstainers (those who didn’t vote for either Mr. Trump or Mrs. Clinton), Democrats won even in rural areas, a Trump stronghold, by 19 points, according to Pew.

Over all, those who sat on the sidelines in 2016 but went to vote in 2018 tended to be liberal or moderate, and they were more likely to be Black or Hispanic than those who had voted for a major candidate in 2016. That reflects the lack of enthusiasm felt both on the left and among voters of color in the last presidential election.

The bounce-back of nonwhite voter participation in 2018 also serves as a reminder to Democratic strategists that Barack Obama’s absence from the ballot in 2016 was not the only factor driving down participation from Black and other nonwhite voters.

The challenge confronting Mr. Biden will be to convince many of those who sat out in 2016, but two years later felt compelled to provide a check to Mr. Trump, that the former vice president is worth voting Democratic again for, even amid a pandemic.