His unwillingness to embrace increasingly popular progressive policies has made him an unappealing option for younger voters who have more or less shunned him in every primary so far, while his legislative and personal history have the potential to put him in a defensive position as we enter the general election.

He is perhaps correctly viewed as the candidate that the Democratic party defaulted to after a contentious primary season failed to produce the centrist frontrunner that party insiders and donors were hoping for. He is the concept of “anyone-but-Trump” embodied in a hollow, flavorless candidacy who is nonetheless plagued by exactly the kind of scandals that would otherwise make Trump vulnerable to criticism.

While he has secured the Democratic nomination for himself on the basis of an argument for his “electability,” many critics have called into question whether he meets that standard. But one thing is certain: If Joe Biden is going to beat Donald Trump in November, it won’t be without a lot of help from the young progressive movement in this country. That’s where Bernie Sanders comes into the play.

On Monday the senator from Vermont and former frontrunner for the Democratic nomination began the long arduous process of convincing progressive voters and activists to rally around a candidate that they find fundamentally dissatisfying. After suspending his campaign last Wednesday, Sanders came out with a statement calling on his supporters to back Biden in order to “defeat somebody who I believe … is the most dangerous president in the modern history of this country.”

It would be disingenuous for Sanders’ endorsement to focus on Biden himself—whose approach to politics Sanders has thoroughly criticized both specifically and in the abstract—but it’s far a more important message than claiming, once again, that Biden is his good friend. Sanders is addressing the significant and terrifying threat that our country faces in the form of Donald Trump. He’s a man who called a pandemic a hoax when swift action could have saved lives, then used it as an opportunity to reward his loyalists at the expense of the public health, all while promoting dubious cures, undermining important regulation, forcing states into expensive bidding wars, and inciting dangerous xenophobia. He is, in short, a reckless, self-aggrandizing, would-be fascist.

In the three years that Donald Trump has held power, he has made tremendous strides in consolidating power for his party, America’s economic elites, and himself. If he manages to get reelected, the problem is going to get worse. Whatever you think of Joe Biden, it’s important to acknowledge how much better he would be for this country. It’s important for the progressive movement in America to (however grudgingly) put their full force behind Joe Biden and get out the Democratic vote—particularly in swing states. While Biden’s VP pick (promising rumors suggest Elizabeth Warren) has a lot of potential to help in that process, Bernie Sanders’ endorsement is an important first step. So why is Bernie Sanders staying on the ballot in upcoming races?

The answer is that Bernie Sanders still represents a huge coalition of Democratic voters, and he wants to be able to represent their interests at this year’s democratic convention. If he is able to secure a large number of delegates for himself, that will hopefully give him the sway he needs to push the party platform to the left on important issues like Medicare for All and student debt relief.

So while Bernie’s endorsement is crucial for inspiring unity in November, voters in states like New York, New Mexico, and Pennsylvania will still have the opportunity to voice their preference for Sanders’ policies.