Perry was not claiming that Social Security is literally a criminal enterprise but asserting that there are similarities between Social Security and a Ponzi scheme.It is probably true that Perry did not literally mean Social Security is a criminal enterprise. It should be noted, however, that Social Security is not a criminal enterprise only by definition. The people who define what constitutes a criminal enterprise say so.
Imagine Social Security as an investment fund offered by a private company. The Social Security "prospectus" makes guarantees it manifestly cannot fulfill, and the executives in charge largely continue to lie about that. Its accounting practices are much worse than those of Enron. Payments are funded in a way which put Bernie Madoff in jail. The major difference between Madoff and the United States government is that Madoff could not legally exact "investments" with the threat of violence.
If Madoff could legally have paid US dollar investments back in Zimbabwean dollars, he'd be a free man. In contrast, those ultimately in charge of Social Security deliberately and continuously debase SS payments to their own advantage. Unaccountably, they are free men.
Social Security would be a better system if it were a criminal enterprise.