Well now you're shifting the goal posts. There's an enormous difference between having the government buy food for a few poor people (which I support) versus being the single payer for food for everyone.

Not really.

There's agricultural subsidies that help farmers to nominally ensure that the US doesn't need to import foodstuffs. That practically guarantees that food is available, but it isn't "single payer" in terms of obtaining that food.

That "single payer" for obtaining food is food stamps. You have to be poor, to very poor, to qualify. But you get stamps, you bring to your grocery store, and you get free essentials, paying with food stamps. The market then redeems the food stamps to the government to get paid. And, guess who prices these essential products? Well let's just say that the government is generally rather stingy about it, but markets that sell these essential items are practically required to accept food stamps, even if only to keep products moving so they don't rot on the shelves.

Food stamps are also agricultural subsidies.

When I was on food stamps there was a long tail where I qualified for a few dollars worth. Always seemed odd.

My understating is the dynamic have changed over time. But for much of its history it was as much about “what are farmers having trouble selling” as it was about “who needs food.”