to claim they’ve done drugs in the WH implies... they got drugs into the WH
or... those at the WH supplied them.
therefore, either the secret service completely missed someone sneaking in drugs, which could easily have been a poison, or... someone in the WH was breaking the law by supplying drugs
which is it
At least when I worked in these environs, when one entered the White House or one of the associated buildings (Old Executive Office Building, etc.), one wasn't checked for drugs. If you had the right credentials, you went through a metal detector, and that was that.
sitetest
Remember, its not breaking the law when the President does it