Economics

And thus the real reason so many politicians opposed single-payer healthcare is revealed.

Until we get all human basics guaranteed to everyone (housing, food, healthcare, water, internet, sewage, trash, electricity, heating and cooling depending on location, etc.) along with a UBI and all large corporations being converted into worker-owned coops, then people will continue to have the "freedom" to live in poverty and/or be subjugated to subpar working conditions.

Or in other words, make it so having a job is optional if those people don't mind living with the bare minimum essentials, and for those who do choose to work for extra, their jobs will have fair working conditions and fair compensation, as the company will be run democraticly. Imagine being able to elect and fire your managers.

And it's not like the US can't pay for it. Even ignoring Modern Monetary Theory (which absolutely applies), we could easilly stop giving tax breaks to the rich, close tax loopholes that the wealthy take advantage of, cut the extremely overinflated military budget, nationalize Big Pharma and hospitals as part of a push towards national healthcare (which would eliminate price gouging for pharmaceuticals and hospital visits for the government's single payer insurance), and stop giving bailouts to Wall St. and corporations every time they fuck up. This would give the US enough money to pay for any damn social services it wants to.

Also ban all private money from politics, change the voting system to something that is more representative, eliminate gerrymandering and the electoral college, etc.