One of the defining features of the Democratic primary has been the age divide among voters — those 45 and over have overwhelmingly backed former Vice President Joe Biden, while those under 45 have generally supported Sen. Bernie Sanders. Now that Biden is the likely Democratic nominee, many political observers have started to wonder whether his lack of support among younger voters will be a problem for him against President Trump in the general election.

According to exit polls from recent elections and polling data from this year, the answer is, not necessarily.

First, Biden is likely to win voters under 45 by double digits against Trump. The former vice president would have two big advantages: He’s a Democrat, and he’s running against Trump. Democrats have won the under-45 vote in every recent election — even in cycles that were terrible to mediocre for the party overall, such as in 2010, 2014 and 2016.

Democrats always do better with young voters Democratic margins by age group according to exit polls in recent presidential and midterm elections Age 2008 2010 2012 2014 2016 2018 18-29 +34 +16 +23 +11 +19 +35 30-44 +6 -4 +7 +2 +10 +19 45-64 +1 -8 -4 -8 -8 -1 65+ -8 -16 -12 -16 -7 -2 Source: Edison Research Group

Compared with other age groups, younger voters overall tend to hold more liberal views on social issues and the role of government. Furthermore, the cohort of Americans under 40 includes significantly more Asian, black and Latino people than the cohort over 40 — all Democratic-leaning groups. But even younger white people tend to vote for Democrats at higher rates than their older counterparts.

Hillary Clinton won the under-45 vote by 14 percentage points in the 2016 general election, according to exit polls, a margin similar to that won by then-President Barack Obama four years earlier. But in the 2018 midterms — essentially a referendum on Trump’s performance even though he wasn’t on the ballot — Democrats won voters under 45 by 25 points. These results in part were likely due to a backlash against Trump among younger voters, who disapprove of the president’s job performance much more so than do older voters.

This isn’t likely to change in 2020. Polls already show Biden with massive leads against Trump among younger age groups. And I would expect that margin to grow if the Democratic Party, including Sanders and his supporters, consolidates around the former vice president.

All that said, a potential problem for the Democrats with Biden at the top of the ticket is not that younger voters will back Trump but that they might either stay home or vote third-party. Maybe Biden would win a high share of younger voters, but they would make up a significantly smaller part of the electorate than if Sanders were the Democratic nominee. After all, the number of 2012 Obama voters who either sat out or voted for a third-party candidate in 2016 rivaled the number of people who went from Obama to Trump, and the Obama voters who turned into non-voters or backed a third-party candidate were disproportionately under 45. Also, some election analysts have argued that Clinton would likely have won the 2016 election if black voters had supported Clinton at the levels they did Obama, and young black voters in particular voted at lower levels in 2016 than in 2012.

Biden’s running into a similar problem is more plausible given that he is similar to Clinton in a lot of ways. Both are fairly old, white, center-left establishment figures who were dominant among older voters and black Democrats in the primaries but not generating much enthusiasm among younger voters.

Indeed, it’s not unreasonable to think that Biden might face the same turnout problems with younger voters that Clinton did, but it’s important to remember that younger people typically vote at much lower rates than older people. In the U.S. there are approximately 74 million baby boomers (those who have turned or will turn 56 to 74 years old in 2020) and around 71 million millennials (age 24 to 39 as of the end of 2020), according to the Pew Research Center. But in the 2018 midterms, about 44 million boomers voted compared with about 26 million millennials.

Young people are less likely to vote, regardless of race Share of respondents who reported voting in each presidential election by race and age Black 2008 2012 2016 Age 18-24 55% 49% 42% Age 25-44 64 65 57 Age 45-64 69 72 66 Age 65+ 68 75 69 White Age 18-24 49% 42% 47% Age 25-44 62 59 60 Age 45-64 71 70 70 Age 65+ 73 73 73 Hispanic Age 18-24 39% 34% 34% Age 25-44 48 47 46 Age 45-64 58 56 55 Age 65+ 56 60 57 Total Age 18-24 49% 41% 43% Age 25-44 60 57 57 Age 45-64 69 68 67 Age 65+ 70 72 71 Source: U.S. Census Bureau

Even in 2008, when Obama’s strong support among younger voters was a huge factor in his winning the Democratic primary, Americans under 45 voted at significantly lower rates than those 45 and over in the general election, according to U.S. Census Bureau data.

Indeed, youth turnout was down a bit in 2016 relative to 2012 and 2008, but to say that shift swung the election is misleading — the race was so close that any number of factors could have swung the election. Clinton also underperformed Obama with 45- to 64-year-old voters. And the older vote remains more important electorally simply by virtue of its size — it makes up about 60-65 percent of the electorate.

All that said, boosting young enthusiasm and turnout should be a major goal of the Biden campaign. There’s a lot of talk in Democratic circles about increasing the number of black and Latino voters in the general election. But black people 45 and over already vote at fairly high rates — significantly higher than voters under age 45, even white ones. The younger the electorate, the better for Biden because, as mentioned previously, younger people are more likely to be non-white, and younger white people tend to be more liberal than their older counterparts.

That last detail really gets at the bottom line: The Democratic primary electorate is so different from the general election electorate that we should assume little carries over. In the primary, a younger electorate helped Sanders; in the general, it will help Biden. In the primaries, Biden has won white voters without college degrees in states like Michigan and Missouri — a group Democrats haven’t carried nationally in a presidential election in more than two decades.

And that’s the point. In a general election, Biden’s set of concerns will be very different from what it has been in the primaries. He should worry a lot more about maintaining support among white voters without degrees in Michigan than among young voters in California. Biden needs to do well with younger voters — but he’ll be trying to persuade them to vote, not necessarily to back him. In short, his problems with younger voters in the Democratic primary aren’t likely to be repeated in the general election. He’ll have a whole new set of issues to worry about.