In 2020, the share of U.S. voters who identified as LGBT rivaled that of other minority communities, influencing who won and lost tight races. While initial exit polls suggested President Trump had surprisingly won more LGBT votes than any previous Republican presidential candidate, more recent data suggests that was not true. In fact, LGBT voters probably played a decisive role in swing states in handling the presidency to Joe Biden.

Here are three things to know about LGBT voters this year.

A larger share of voters identified as LGBT than in any previous election

The LGBT population in the United States is growing, with an ever-greater number of young adults identifying as LGBTQ: In 2019, the Centers for Disease Control and Prevention found that 16 percent of high school students, and 22 percent of girls, identified as LGBTQ.

Now the electorate is catching up. Exit pollsters began asking voters whether they identified as lesbian, gay or bisexual in 1992, adding transgender in 2016. Until 2018, the proportion of the electorate identifying somewhere on the rainbow continuum has ranged from 3 to 5 percent — roughly the proportion of the U.S. population who say the same. But this year, it jumped to 7 or 8 percent.

Those are the results from two major election surveys: the National Exit Poll conducted by Edison, whose estimates are still preliminary, and the AP VoteCast conducted by the nonpartisan and objective research organization NORC at the University of Chicago. These surveys differ in their methods. The National Exit Poll surveyed in-person early voters and on Election Day and absentee voters by phone. The AP conducted large probability-based surveys in addition to opt-in online panels. Both surveys ask about LGBT identification.

Why so many? One source is younger voters, as the Gallup Organization found 8.2 percent of millennials identify as LGBT, while only 2.4 percent of baby boomers do. These young generations appear to be showing up to vote. Further, people across all generations are increasingly likely to self-identify as LGBT, given the sea change in public acceptance. Finally, more LGBT people may be turning out to vote; for some younger ones, this was the first presidential election in which they were old enough to vote.

LGBT voters overwhelmingly supported Biden, but more supported Trump than in 2016

Voters who identify openly as LGBT overwhelmingly tend to vote Democratic. Despite the Trump administration’s “Trump Pride” rallies, this continued in the 2020 election.

The National Exit Poll reported that 64 percent of LGBT voters favored Biden and 27 percent supported Trump. If that’s true, Trump received the highest percentage of LGBT support any Republican presidential candidate has ever received — and LGBT support for Trump doubled since 2016. However, AP VoteCast found that 73 percent of LGBT voters supported Biden and 25 percent Trump, more in line with years past.

So which is more accurate? To find out, we compared estimates of the percent of the LGBT electorate across the states and nationally documented in both the National Exit Poll and the AP polls and its relationship to the percent of adults who identify as LGBT. While the two measures are not exactly the same, we should expect to see a roughly comparable percentage of LGBT voters and of LGBT adults across the United States.

The National Exit Poll state estimates of the LGBT vote are not very comparable to the size of the LGBT adult population; the AP VoteCast estimates are modestly comparable. Given potential inaccuracies in the National Exit Poll in documenting LGBT vote share, we believe this to lead to inaccuracies in describing the LGBT vote.

Even in the AP poll, LGBT support for the Democratic candidate does dip slightly compared with 2016. But that’s because in 2016, the Republican presidential candidate received the lowest share of LGBT voters since it’s been documented. Apparently, in 2020, conservative LGBT voters began returning to the Republicans.

LGBT voters probably made a difference in battleground states

Along with several other minority groups, LGBT voters may have helped tilt some swing states for Biden. In key states like Arizona, Georgia, Nevada, Pennsylvania and Wisconsin, most LGBT voters went for Biden, while a majority of non-LGBT voters favored Trump.

In Georgia, for example, Biden won narrowly with 49.5 percent of the vote to 49.3 percent of Trump’s vote. According to AP VoteCast, 53 percent of non-LGBT voters cast ballots for Trump. In that state, LGBT people made up 9 percent of the electorate, which means that 88 percent of LGBT voters had to choose Biden for Biden to win.

We find similar results in Arizona, Nevada, Pennsylvania and Wisconsin. In the table below, AP VoteCast gives us the percent of a state’s voters who identified as LGBT and the percent of non-LGBT voters who went for Trump and Biden. We calculated the percent of LGBT voters who went for Biden or Trump by determining what these would have to be, based on the other information. According to our calculations, 89 percent of LGBT voters in Arizona supported Biden, as did 73 percent in Nevada, 78 percent in Pennsylvania and 70 percent in Wisconsin.

Had LGBT voters stayed home, Trump might well have won the 2020 presidential election.

When races are close, LGBT Americans, who tend to vote in high numbers and have been reliable Democratic supporters, can make the difference in favor of Democratic candidates. With the number of people openly identified as LGBTQ steadily growing, LGBT voters may well help determine future elections. That includes Georgia’s January Senate runoff elections as well as future local, state and federal elections.

Andrew Flores (@DrAndrewFlores) is assistant professor of government at American University and visiting scholar at the Williams Institute.

Gabriele Magni (@gabmagni) is assistant professor of political science at Loyola Marymount University.

Andrew Reynolds (@AndyReynoldsPU) is a faculty member in the School of Public and International Affairs at Princeton University.