Sen. Bernie Sanders has won his second congressional endorsement from Rep. Keith Ellison (D-Minn.), one of Congress’s two Muslim lawmakers.

Ellison follows another progressive, Rep. Raúl Grijalva (D-Ariz.), in endorsing the Vermont Independent for president. Ellison and Grijalva are co-chairmen of the Congressional Progressive Caucus, a group Sanders helped start when he was a House member.

“I’m endorsing Bernie because he is talking about the issues that are important to American families,” Ellison told MSNBC Monday in an email from a representative.

“His candidacy is important for many reasons, but I believe the most important part of his candidacy is that it has the ability to create a renaissance in voter participation, which was at its lowest in decades this past election cycle. We’ve all seen the massive crowds he is attracting, and I think that is a testament to his message connecting with people — people we will need to turn out in November.”

Sanders is trailing Hillary Clinton when it comes to congressional endorsements. The Hill’s endorsement list shows that Clinton has the backing of 93 House members and 30 Senators, including Vermont’s other senator, Patrick Leahy (D).

But the first two endorsements are notable for Sanders and come as he’s continuing to close the gap with Clinton ahead of Tuesday’s first Democratic debate.

Clinton still holds a strong lead in most recent national polls, between 7 percent and 20 percent. But Sanders has overtaken her in New Hampshire and cut the margin dramatically in Iowa.

Ellison told MSNBC that he wasn’t worried about Sanders’s lack of support in Congress and that he’d be willing to act as a surrogate for him.

“What matters is that he is connecting to the American people and talking about issues that matter to them the most,” he told the network.

Former Maryland Gov. Martin O’Malley, who is at a distant third in all polls of the current Democratic field, is endorsed by Rep. Eric Swalwell (D-Calif.). Swalwell announced his support in July. Outside of those three lawmakers, and two who back Vice President Biden, all others are either aligned with Clinton or haven’t chosen a side publicly.