Supporters of Rep. Keith Ellison (D-Minn.) and former labor secretary Tom Perez, candidates for Democratic National Committee chair, attend a Feb. 11 forum in Baltimore. (Joshua Roberts/Reuters)

The president of the International Longshore and Warehouse Union has endorsed former labor secretary Tom Perez’s campaign to chair the Democratic National Committee. It comes as the Service Employees International Union told members who have a vote in the DNC race to back Ellison.

“The next DNC chair needs to put the concerns of working families first, and my personal experience with Tom Perez showed me that he is a skilled problem solver who is committed to America’s working families,” ILWU International President Robert McEllrath said in a statement. “Tom Perez helped the ILWU at a critical time in our negotiations, and working with him gave me the opportunity to see firsthand that he is hardworking, trustworthy, and a straight shooter — all qualities I admire. I maintain the utmost respect for all of the other progressives who have stepped up to run for DNC Chair, especially Congressman Keith Ellison of Minnesota. But my personal experience seeing Tom Perez work hard to solve problems for my union’s membership is what makes this the right decision for me.”

Ellison, who jumped into the race five weeks before Perez, won early endorsements from labor unions and from Sen. Charles E. Schumer (D-N.Y.). McEllrath endorsed Bernie Sanders in the 2016 Democratic presidential primary.