[mrandish]

Yes, it's a serious problem but even onerous approach you describe has a fundamental weakness. Since even prisoners in jail are able to obtain and use drugs, we should expect such a system to have failures and due to the nature of aggregated political power. Even a small number of such failures can have outsized negative consequences.

There is an alternative approach to mitigating this problem which is easier, cheaper and more effective. We need to reduce the concentration of political power by making politicians and beaurocrats less powerful. Since the benefits of political power tend to amplify over time, we should limit all such positions of power to single terms. Once elected to any state-wide or national public office, you can never be elected to another. One and done. If there are no 30-year career politicians, the value of influencing them is greatly diminished.

The next step is to reduce the amount of power centralized within government. Much as bank robbers target banks "because that's where the money is", crony capitalists and lobbyists seeking regulatory capture target politicians because we've allowed too much power to pool in one place.