Rohrlich notes they enjoy “a substantial informational advantage compared to ordinary investors and even corporate insiders.”
And he further notes:
[C]ongressional ethics rules specifically state that members must not use privileged information gleaned during the course of their duties for personal gain. But the rule is just a rule; it is not legally binding, and the SEC has never brought an enforcement action against any member of the Senate or the House.
Insider trading is illegal for you and me and standard operating procedure for our government overlords, er, representatives.