The way things are shaping up, the Democrats and labor are congealing around the position that the projected budget surpluses should be 'dedicated' to Social Security, and trying to exploit the fact of Trust Fund surpluses (which roughly equal aggregate budget surpluses over the next decade) being 'threatened' (sic) with tax cuts.
I think this is a very very bad position to take. It tends to ratify the non-social security budget deficit (the "on-budget" deficit) as a new standard and imply this deficit should be routinely kept at zero. This is another way of saying the surpluses should be placed off-limits to spending, and that unified budget deficits are completely out of the question.
The dedication of the budget surpluses to "save Social Security first" could take the form of simple debt repayment, or the trust fund purchase of stock. I'm more troubled by the assumptions underlying this policy, then the actual acts of debt repayment or stock purchase.
While I share your jaundiced view of the stock purchase idea, it should be noted that state pension funds are pre-funded in this way and there is no overarching political-economic issue that I can see in that context. The individual accounts, a transition to which would be facilitated by the trust fund purchase, would be a big deal.
Putting aside the budget issue, labor would gravitate towards some variation of the Ball plan, which included a stock purchase as part of their solution.
MBS