Didn't you notice that this was on a "COMEDY" page?
But, let's look at this as if the story is totally true... Why would they revoke his license?
There could be several reasons:
1. He is not currently a practicing physician.
2. He does not currently have an active association (residency) with a hospital.
3. While perusing political office, he's probably not keeping up with changes in medical procedure. (Accountants have to take continuing education classes to keep a CPA license. I assume doctors have to do the same to keep a medical license.)
4. He probably is no longer carrying the insurance needed to practice surgery.
5. He probably is no longer jumping through the hoops necessary to meet governmental regulations and requirements.
See, there are a number of reasons why this may be the case, but until you can cite a source better than a "comedy" page, there is no reason to believe it!
After all, most reasons can be eliminated if he wants to return to medical practice. All he would have to do is to again meet the requirements to be re-certified.