On everybody who has an income
And suddenly the bottom 40% just died because they're currently paying no taxes (because they don't meet the threshold for taxable income due to not making enough money).
Everybody gets 1500 USD a month, but pays 50% of their current income.
This makes literally zero sense. It would create more bureaucracy and administrative waste than simply doing it the current way--that is, via tax credits/rebates.
Just check out average income times income-receivers times 50% and deduct 1500 USD times every US citizen (don‘t forget children and pensioners).
Average income: $30,000.1
Income-receivers: No idea what this really means and I could find zero figures on it, but let's say 250,000,000.
US population: 325,000,000
So we have 30,000 * 250,000,000 * 0.5 - (1500 * 325,000,000). That equals to 3,262,500,000,000 which, yes, would pay for it. However, it completely disregards that we're taxing someone making average wages ($30k) down to nearly poverty level. That's simply not reasonable.