Only really because of what's left of the welfare system, mainly Medicaid, Section 8 housing, food stamps, and the EITC; which I agree does help on the low end, but is increasingly being time-limited and rationed (e.g. Section 8 is hard to get into). The 10th-percentile household income in the U.S. is around $12,000. If that's all you had to live on, even in cheapish parts of the US it'd be quite a stretch to pay rent+food+transportation+healthcare out of that, especially for more than one person.
The problem is that a society where everybody have similar incomes is somehow fairer, when there is no logical chain leading there and to top it off it causes ruination.
Well, I've lived in both the U.S. and Denmark, which have very different levels of income inequality, and I wouldn't say Denmark has suffered ruination. There are pros and cons, of course. The logical chain isn't that complex if a society actually wants to implement it; it doesn't require some kind of communist revolution, just high and highly progressive taxes (including on capital gains), a national healthcare system, and a strong safety net.