Things might not be that bad. This page from Statista says that US Govt expenditure is a bit over 35% of GDP in most years lately and that it exceeded 47% in 2020: https://www.statista.com/statistics/268356/ratio-of-government-expenditure-to-gross-domestic-product-gdp-in-the-united-states/

The figures are practically identical for New Zealand which has a welfare state, but threadbare these days thanks to 35 years of neoliberal cuts (e.g. no affordable dentistry, no universal child benefit). For the EU and the Euro area govt expenditure is typically 47% in a normal year. So in other words the USA could become a social democracy but it would have to treat every year as if it were 2020 from now on.