Washington (CNN) Democratic Presidential candidate Bernie Sanders will receive his first congressional endorsement this week: Arizona Rep. Raul Grijalva.

The liberal Democrat is set to announce his support for the Senator's presidential bid during a rally in Tucson on Friday, just before Sanders heads to the first Democratic debate in Las Vegas next week.

Grijalva is currently in his seventh term representing Arizona's third district. He is co-chairman of the Congressional Progressive Caucus, which was co-founded by Sanders, and a long time member of the Congressional Hispanic Caucus.

Top Democratic candidate Hillary Clinton has racked up more than 100 endorsements from Democratic members of Congress since she announced in April.