I like to approach such nonsense by objective analysis, finding the outer limits of the issue and seeing how advocates react to "ok, so you'd agree to X? really? didn't think so."
Of late there is a FR thread on tiny homes. Short version is: one can get a decent livable 100 sq ft home (yes, you read that right) for $10,000, land extra. We can assume an equal amount for related expenses over 10 years. My tagline points to my blog on a related subject: you can live on $3/day for food. Quick juggle the math, assume capital expenses amortized over 10 years, generous round-up to catch other expenses, and I figure we'll be handing out $10/day.
$10/day.
Far from luxurious in our culture, sure, but enough for a respectable baseline which is 5x the world median income. It ain't "poor".
1/3rd of the population pays taxes. Assuming, in fairness, anyone paying taxes will thus be "assigned" two people to support. Federal income tax revenue is about $1T/yr. 200,000,000 people at $10/day is $0.73T, leaving $0.27T - just enough to cover federal debt interest.
Ya know, this could work.
There is just enough federal revenue to do it. (Bet the ones asking the original question and the ones answering "yes" didn't think it would work out this way.) Just dump all government spending outright, and redistribute that income tax revenue as a universal basic grant. What little revenue remains fulfills basic obligations of interest payments, a basic border-defending military (call up the militia!), and a tiny bureaucracy for miscellaneous other things; all other departments either self-fund (DoI parks pay for themselves, USPS customer-funded, etc.). Eliminate the IRS and just have the states & territories send the White House a total of 50+13 checks per year; let local jurisdictions figure out how to raise the money.
Voila: deficit eliminated, everyone gets a basic 5-times-world-median standard of living safety net, DC is reduced to four buildings (Capitol, White House, SCOTUS, and Pentagon), conservatives and liberals are satisfied alike.
So, people who answered "yes" to the lead question: you'd agree to providing every single American a basic income grant? really? $10/day, resulting in the complete elimination of nearly all other federal spending? didn't think so.
Median income in the US is around 32k for all adults. There are about 200 million working age adults, making total personal income of 6,400,000,000,000. To give 350 million people $5,000 each would cost 1.75 trillion. That works out to about a 36% flat tax, just to pay the basic allowance. However, each taxpayer receives a 5k rebate making the net effective tax rate much lower. Only a 0.75 trillion hit or about 8% average tax. You would have to figure out the transition but if it ended all entitlements it might be more sustainable.