Honestly, banning lawmakers from trading stocks might just push it into blind trusts or family accounts, so the trading still happens but harder to see. I get why people want a ban, but I'm not sure it actually fixes the problem.
A surprising fact is that disclosure rules already exist in many places, yet people still don't trust them. You make a fair point about bias, I honestly don't know how to argue that away. I just think a ban might make trading sneakier through trusts or relatives.
They're the government. If people find out the government is doing something bad, even one member, then its gonna all be bad, ESPECIALLY FOR THAT PERSON.
I get your point about bias, that part makes sense. But imagine someone just hands trades to a relative or a trust, the money still flows and voters see less. I just feel a ban pushes it underground rather than stopping it.