I would respond on three levels. One is that you must have very tight security and detection at the gates. The best deterrent is your risk of getting caught, not the risk of the magnitude of the punishment. The higher the likelihood that you'll catch people at the gate, the more you will deter.
The second level of response has to be that your family member with the drug problem in prison will get care and support for that. You don't have to do that misplaced caring that you think you're doing by bringing drugs in. The more the prison and the health authorities within prison are saying to families that there is care and support for people who are dealing with these problems, the less families will need to keep fueling those problems.
The third response is dealing as much as you can with the family systems themselves that people will return to, even though in the federal system it will clearly be two years or more before they will get back, and there might be greater distance from the family. The more you can do that and reach out to the healthy members of the family rather than the co-dependent or co-addicted members of the family, the better long-term-recidivism impact you might have.