As his star rises, Mamdani, a democratic socialist, has also been flexing his political power in new ways — his endorsement of three progressive candidates for the House of Representatives gave them the edge against establishment-backed incumbents and contenders, and cemented his role as a kingmaker in the Democratic Party. Mamdani, of course, also has many detractors, on the right but also among Democratic leaders in Washington who worry about his influence and his aims in pulling the party further to the left.

(http://www.autoadmit.com/thread.php?thread_id=5883835&forum_id=2E#50008015)