Sen. Bernard Sanders, I-Vt., one of the Senate’s most liberal members, has endorsed state Sen. Daylin Leach — one of four Democrats running in the primary for Pennsylvania’s 13th District .  

Sanders joins a crowd of liberal Democrats in Congress who are backing Leach, including the Progressive Caucus Co-Chairs, Reps. Raul M. Grijalva of Arizona and Keith Ellison of Minnesota, plus Alan Grayson of Florida.  

“At a time when our country has more income and wealth inequality than any other major country on earth, and when the gap between the very rich and everyone else is growing wider – it is imperative that we send candidates like Daylin Leach to the U.S. Congress,” Sanders said in a news release Monday. On May 20, Leach will face off against former Rep. Marjorie Margolies, physician Val Arkoosh and state Rep. Brendan Boyle in the Democratic primary for this open-seat race .  

The seat is open this cycle because Rep. Allyson Y. Schwartz, D-Pa., is running for governor.  

Pennsylvania’s 13th District is rated Safe Democratic by Rothenberg Political Report/Roll Call.