Is the voting in their legislature anonymous? Why?

Unlike ordinary people, the legislators are working for their voters, who deserve to know if they got what they paid for. If I send Bob to the legislature, understanding that he plans to get rid of all the bloody clowns, I certainly want to know if he supported the Bill that gives every Clown $5000 of the city's tax revenue to buy more ludicrous shoes and lapel flowers. If Bob can promise he's anti-clown, then arrive in the legislature and vote a straight pro-clown slate knowing he'll face no consequences, that's no way to run a representative democracy!