To be clear, he is not elected. He won the democratic party nomination for the senate from Michigan. He is prominent because he is Muslim and progressive and is not the kind of candidate we usually get from the democrats for a seat this important. Most of the prominent democrats (elected or in party leadership) had supported his opponent. Also much more money was spent against him in the nominating race than for him. And much of the funding supporting his opponent (or denigrating him) was from AIPAC.