Sanders, Feinstein oppose criminalizing BDS

Yes, Congress is adding a rider to the spending Bill that would make it illegal to support the Boycott, Divest, Sanction (BDS) movement. It is called the Israel Anti-Boycott Act. Sanders and Feinstein, while not supporting BDS (why not?)  do say this Act is a violation of free speech. What's behind the Act? What else, the money the Israel lobby gives to legislators. They are literally selling out free speech. Also see this prior post for more of the motivation.