People won't pay. Not at least here where I live. They will probably steal electricity, water, internet. Hell, some of them are doing it now. Maybe US has some kind of utopian society but I know the society I live in too well to think that would work.
Not paying to support bums is a benefit in itself, too. People seeing homeless bums who were irresponsible with their money will likely be scared into doing things like buying only what they need, saving for emergencies, and working with neighbors to avoid or overcome any issues. Things people in countries with little government support do (compare the family and savings culture of Chinese to the family and savings culture of Europeans and Americans who get Social Security and pensions). People don't learn responsibilities if they aren't shown consequences of ignoring them.