Just place all their assets into a blind trust, perhaps a "congressional employees' index fund", for the duration of their employment plus n years. There are many obvious loopholes, like all assets in your spouse's name, etc, but maybe there is a lookback period or something. There are much thornier compliance problems that are solved, so all the what-ifs can likely be addressed with precedent.

They already get generous pensions.

But yes, cap their wealth, limit their stock investments to broad market ETF for stocks and bonds. Extend this to spouses and probably children (for a term). Perhaps provide them with housing in Washington DC.

And attempts to bypass the limits should have very harsh punishments.

Politics should be like teaching - no one does it for the money.

That cap better be near a billion.

If you were the VP of some company with a trillion dollars of revenue your compensation wouldn't be under a million/year.