According to a former advisor to the Central Bank of China, the answer is yes. Despite the myopic view among likes of Paul Krugman and George Soros, the sovereign debt of the U.S. is not such a great bargain because Fed buying of Treasuries has kept bond prices artificially high and unsustainable over time. Like water finding its level, bond prices, too, "will eventually fall to reflect the fundamentals of the U.S. economy".
The mantra of the left, that debt does not matter, is counter intuitive to all common sense, logical economic thought. Flooding the monetary system with worthless money that has no corresponding economic output, eventually results in CPI inflation given sufficient economic activity. An inevitable byproduct, debased currency, bodes poorly on bond prices and confidence of foreigners in that economy. Reduced confidence by foreign investors lead to difficulty in raising debt without increasing interest rates to sky high levels.
The eventual victims? Every single U.S. resident.
Yes, U.S. Treasuries have become a ponzi scheme because they are there to finance other ponzi schemes - namely entitlements like social security.