"MMT argues that public deficits create private surpluses, since the government adds more money into circulation that it subtracts. Private surpluses lead to more bank deposits, pushing interests rates down, not up."

I am not an economist, but I can read a spreadsheet. If the federal government doesn't spend more than it taxes there simply is no uncommitted money in the economy to purchase bonds. It isn't that there isn't a desire for interest-bearing investments, regardless of the rate, but that there no demand, as we saw during the budget surpluses of the Clinton era.

The "aha" moment for me was when I realized that deficit spending "funds" bond sales, making them a depository for past productivity, not an encumbrance on future productivity. It then follows that a "balanced" budget represents the theft of the sum of resources and labor the government uses. Clawing back all payments to the private sector to achieve a mostly irrelevant numerical balance seems, to me, to be a far greater detriment to the economy than even the slight risk of inflation posed by a more equitable economy.