Did Coleman really change his last name so people wouldn't know he is Jewish? Or am I thinking of the wrong guy?
yes, he did do that.
Wow. What a loser. This is just me, but if I seriously thought that the ethnicity or religion implied by my last name was in itself a disqualifying factor to be able to gain elective office as a Republican, I'd change my political affiliation, not my name.
I don't know whether he changed his last name, but if he did, it was long before he became a Republican. He was originally elected as a Democrat, not a Republican, under the name 'Coleman.'