BONNER SPRINGS, Kan. (AP) — U.S. Sen. Bernie Sanders is endorsing one of his 2016 presidential campaign volunteers in the race for a suburban Kansas City congressional seat.

Sanders on Monday threw his weight behind lawyer Brent Welder. He’s one of six Democrats seeking the Democratic nomination for a Kansas congressional seat currently held by Republican Rep. Kevin Yoder. Yoder’s seat is a top target for Democrats because President Donald Trump narrowly lost the district.

Welder served as a delegate for Sanders at the 2016 Democratic National Convention when he was a resident of Missouri. Welder, who now lives in Bonner Springs, Kansas, also worked as a grassroots organizer for Sanders’ presidential campaign. Sanders described Welder in a statement as a “bold progressive.”

The primary is in August.