Going to have to go back through my posts and find that link. Some site claimed that the leaders of the Clinton campaign in 2015-2016 said that Sanders was ineffective in Congress due to being rigid and unliked.

I saw seven bills passed since he first joined the House of Representatives in 1991, two of which were postal facility renamings. And though https://www.govtrack.us/congress/members/bernard_sanders/400357 says that passing only 7 bills since 1991 is not ineffective, realize that's less than one every three years for the past 29 years.