Doesn't the US already have the most progressive tax system in the world? If you want more public services the tax rate would need to increase at all levels but dramatically so at the middle to low end.
The U.S. tax system is less progressive than those in many other industrialized nations. European countries like Denmark and France have higher top marginal tax rates (above 50%), while the U.S. top federal rate is significantly lower. Additionally, U.S. taxes and transfers do less to reduce income inequality compared to peer countries.
Raising rates on soley the rich will make the tax system even more progressive but will probably not make public service much more generous. Raising the tax rates on everyone would probably make the tax system less progressive but might actually fund a large increase in public spending.
What matters is outcomes, and the U.S. system—compared to other developed nations—does far less to redistribute wealth or fund robust public services. Other countries raise more revenue overall (often through broader-based taxes like VAT), and they spend it more equitably. So yes, technically progressive—but practically insufficient.
It's arguable, but it's safe to say that it's one of the most progressive among development countries, but that's in large part a function of the comparative inequality and low tax rates to start.
> If you want more public services the tax rate would need to increase at all levels but dramatically so at the middle to low end.
Yeah, but the net effect can be an improvement in terms of inequality. See e.g. https://www.cbpp.org/research/what-do-oecd-data-really-show-...
"As a result, the latest OECD data show that while the United States has the tenth-highest level of income inequality of the 31 OECD countries examined before considering taxes and transfers, it has the fourth-highest level of inequality after considering them."
"As the OECD report notes, if two countries have identical tax schedules that include graduated marginal rates, the tax system will have a more progressive impact in the country with higher pre-tax inequality, because a larger share of that country’s income will be taxed at the top rates."
"Because of their comparatively small size and below-average progressivity, U.S. cash transfers do less to reduce inequality in household cash incomes than those in any other OECD country except Korea"