Politically, sure, they allow you to do the reverse starving of the beast thing (wherein you fund services by deficit spending, thus making tax increases more palatable to public, as those services had time to prove their worth) but practically?
That really shouldn't matter that much.
MMT or no MMT, you still want to reach a long term balance of revenue and spending to avoid the inflationary pressures that a chronic and systemic deficit brings.
It's not MMT or no MMT, because MMT demonstrates that a government has to have a "chronic and systemic" deficit for an economy to grow. Which means that a government has to create more financial assets for the private sector to use in the economy over time. If you look at the history of the US government, it (appropriately) has a "chronic and systemic" deficit. In the last 30 years, the government has only net taxed four. And those were four consecutive years that then produced a recession. The only exception to this is if you maintain a positive trade balance with the rest of the world (e.g., Australia). But that basically just means that you are sending more real wealth (physical goods) out of the country than you are bringing in from other countries, i.e., a net loss to the society in
real wealth.
A chronic and systemic deficit does not bring inflationary pressures. Spending
too much
too quickly does. A chronic and systemic deficit is merely a record of past spending. It has no further implications. Inflation can't occur now because of how much money the government net spent in 1985.
The only real problem of relying exclusively on taxation are times of serious economic slowdowns (recessions, natural disasters), and that's what federal aid should be for.
I do not believe states will be able to successfully implement single payer systems. They will be subject to all kinds of forces--fiscal, (then) political, and economic--that will almost guarantee them to be inadequate. Not to mention that such systems will
not have full monopsony buying power. A state's ability to set prices will be compromised by the sellers having other convenient options (next state over!). Another problem with federalism!
We should just do it rationally and implement a national health insurance program. And people should organize politically for that demand.