Instead of back room poker games, we have organized drug dealing. 

This is not a situation described in PA landlord law - like evicting a tenant who is selling drugs)As most everyone has said here, I'll deal with the inherited tenants with empathy, professionalism, and courtesy (I would anyway); and if in the worst case, I have to work around them for a period of time, so be it.

CRIME-FREE / DRUG-FREE: You, a guest or other person under your control shall not engage in illegal activity on the Premises or near enough to adversely affect it or other residents.This includes:a.

Basically they are harassing my tenants by calling the police on them nearly every day for various completely made up reasons, such as drug use, shouting, disturbing the peace, public drunkenness etc. 

Use of illegal drugs by all Tenants is prohibited, (including marijuana).

@Sean Hayes we own parks around atlanta, are licensed dealers etc.

Lease the property that needs no special requirements other than ADA type issues to a care provider such as your local mental health association affiliate or possibly a drug rehab or ambulatory clients.

I am guessing this clause was put in place to prevent homes from being pulled out of parks by known dealers. 

In other words, I look for a good deal and let someone else take that big loss by driving the new car off the dealer's lot.Mike

Due to a clause in the existing lease regarding drugs, I think I have grounds to evict, but along with that there is another clause about being considerate of the "rights, comfort, health, safety, or convenience of others."