Article I, Section 8 of the Constitution articulates ALL of the powers that Congress has to spend money. The Tenth Amendment reserves all powers not delegated to the Federal government, "...to the states respectively, or to the people."
Thus, Congress lacks the power to tax individuals (or corporations) for the purpose of supplementing the incomes of those at the bottom, whether such supplementation is in cash or in kind (free food stamps, free housing, free anything). Much of what the Federal Government does now is unconstitutional and, ironically, would not pass constitutional muster under the guidelines articulated by CJ Roberts in the ObamaCare decision.
(Parenthetical: The terms, "fortunate" and "less fortunate" drive me crazy. Most people making a lot of money are able to do so because they have educated themselves either formally or informally, and have worked their asses off. Most people making MW and thereabouts are at that level because that is equivalent to the economic value of their labor. "Fortunate" and "unfortunate" have nothing to do with it. It is a nauseating liberal conceit to refer to those with high incomes as "fortunate," because it denies the worth of their efforts. And the same is true at the other end of the spectrum. Some are wealthy because they are fortunate and vice versa, but in the majority of cases, people have wealth and incomes that befit their talents and perseverence. Luck has little to do with it).
The "death of the middle class" is not just liberal mouth flatulence. I am old enough to remember when a HS grad with little ambition could amble on down to the local steel mill, construction site, or manufacturing shop and, with the help of a strong union, be set for life by age 25. He would have a non-working wife, a couple kids, a house, and a new pickup truck, and rest easy at night knowing he could essentially never lose his job, and he could retire at age 55 or so with a guaranteed lifetime pension.
The "global economy" has killed this life style (unless you work for GM or Chrysler, or the [*******] Government), and there is NOTHING the United States government can do to bring it back. Pretending that any government program will restore this middle class option - and this is what they are talking about - is absolute nonsense, and those who pathetically cling to the Democrat Party and "progressive" promises of prosperity for the "poor" are as clueless as Lenny dreaming about the rabbit farm in Steinbeck's novel, "Of Mice and Men."