Given that the US has a population of 342.7 million people [3], those two trillion dollars divides out to $5800 per resident per year.
The UK's universal healthcare system costs ~$4700 per person per year (~£3,500)[4].
If we could spend healthcare dollars as efficiently as the UK, the current government spending in the US is enough to support a single payer healthcare system covering every resident without raising taxes.
[1] https://www.cms.gov/data-research/statistics-trends-and-repo...
[2] https://www.kff.org/medicaid/medicaid-financing-the-basics/#...