A good quote from the past (courtesy of my brother)..
In 1937, "Arthur Altmeyer, head of the Social Security board, came under heavy fire at a Congressional hearing. Looking for a way to safeguard the reserve, he made an intriguing suggestion: why not let the government invest in sound private securities, and thus insulate the surplus from Congress's eager hands? As Altmeyer recounted in his memoir, Arthur Vandenberg, a Republican senator from Michigan, threw up his hands and snickered, ''That would be socialism!''
Roger Lowenstein (2005) A Question of Numbers
I'll observe that Canada's social security reserves are invested by a board that is appointed by the government.