100% legal. they carved out exemptions specifically for themselves, and forced a 30 day delay on normal humans from knowing what they purchase/sell. in writing.
Legal in that there isn't a specific law against it. Several Reps and Senators at various times have proposed a ban on Congresspeople trading individual stocks (presumably they could still have index funds, mutual funds etc.) but shockingly enough those measures didn't pass.
We need to get the entrenched old guard democrats out of power. They are controlled opposition just as beholden to the billionaires who pull Trump’s strings. We need new blood.