When younger Americans did swing to voting in the 2020 Democratic primaries, they usually cast ballots for Sanders by large margins, even in states that Sanders lost by large margins. Take Michigan, where Biden won by nearly 17 points. Sanders won 18-to-24-year-olds by 61 points; 25-to-29-year-olds by 56 points; and 30-to-39-year-olds by 19 points—while losing 40-to-49-year-olds by 6 points; 50-to-64-year-olds by 44 points and voters aged 65 or over by 52 points. Biden prevailed in Michigan because the two oldest voting categories cast a decisive 52 percent of the ballots.

Sanders needs to grow the share of the youth vote in the Democratic primaries to overtake Biden’s delegate lead. But the opposite has happened thus far. According to exit polls, in no state on Super Tuesday that catapulted Biden into the lead did people younger than 30 make up more than 20 percent of the electorate, and in most states they accounted for 15 percent or less. Younger voters have represented an even smaller share of the Democratic primary vote totals than they did four years ago, according to exit polls.

But why? Why does this age voting disparity exist and persist? Why is it growing? Some Americans have been taking the easy way out—people blaming. It is easy to blame Sanders and his supporters for naively relying on the unreliable youth vote to carry him to the Democratic nomination. It is easy to blame the Sanders campaign for not turning out the youth vote. It is easy to blame young voters for not turning out for Sanders—all their rallying in person and on social media failing to result in voting. But what if something else is happening?

There are only two causes for the historical and ongoing voting disparities between younger and older Americans. Either there is something wrong with young Americans as a group or there is something wrong with our voting policies. Either other swing voters are unreliable, or our voting system is unreliable. Either there is something wrong with people, or there is something wrong with policy.

There are certainly young individuals who are unreliable, lazy, cynical, self-absorbed, or apathetic. But there are older individuals who exude these behaviors, too. To say the reason young Americans are voting less than older voters is because younger Americans are more unreliable, lazy, cynical, self-absorbed or apathetic about politics than their older counterparts is to say that something is wrong with young Americans as a group. To say that something is wrong with young Americans as a group is to say that something is inferior about young Americans as a group. To say that something is inferior about any age group is to express an ageist idea. To say young Americans are lazier than older Americans is just as ageist as saying older workers are lazier than younger workers; it’s just as ageist as saying older workers are checked out and younger workers are having to pick up their slack.