Right, if we really began pursuing UBI, the sales pitch to the right would inflame the left. That's thousands of government jobs administering the current social program sector that would be instantly lost. Tens of thousands maybe. Because to sell it to me, it's a replacement of everything.
Social Security and Medicare go away. Food stamps goes away. Housing assistance and mortgage subsidies. Tax-deductible children and other dependents. Everything gets massively reduced on the government level. This is because that's the only way to pay for it.
When I think about UBI, for it to really work, assuming it didn't disrupt prices too much (and I think it might, if everyone is getting x amount/mo the temptation is going to be rent is now minimum x) but I have enough faith in competition to assume that prices would stay relatively the same, I come up with about 12k/yr.
So 1k/mo for everyone, for life, starting at birth. So that first year of life, tough to make ends meet, you got your birth, that was a kick in the jewels, hospital, vacs, clothes, food, diaper, but whatever, you have parents.
But a family of four, that's 48k/yr. Easy to live an awesome life on that. Can even be saving/investing in the future on that. But a single person can maybe even swing living alone on only 12k/yr. So lets go with that as our number, it's a generous UBI to be sure, but lets go with it.
About 318 million peeps in the US (source, the interwebs). At 12k/year I did some rough calculations and came up with 3.8 trillion dollars or so.
The good news is, that's a number that is possible for our civilization. The bad news is, that's a fucking huge number. It's way more than we're spending on the social safety net right now.
So right there, you feel like a raving lunatic talking about it.
But what is important to understand is that while this would mean doubling the tax rate, you get twelve thousand dollars a year.
So for me, I'd pay roughly an extra 12k per year in taxes, but I'd get all that back. And I could drop all kinds of insurance I carry now, because of the certainty that the 12k was going to be there always. Ahh, but right now I get all kinds of deductions that are going away. The pre-tax contributions? Gone. No more IRA, no more 401k, no more any of that stuff. No more deductible health insurance, nothing. Everything we "spend" by not collecting is all gone. So I'd actually be paying closer to 24k extra per year, bringing my total up to 24k after I get the 12k back (assuming I paid 12k before). Now, I'd still sign on to this, because if I ever had a couple kids I'd be at zero taxes (cuz I'm fucking taking their UBI cuz I'm bigger and so I will).
So that's where I'm at, I think the number is too big. We either need to grow the economy a lot (like, so much) or something is going to have to go horribly wrong (the robot revolution). Because I don't think 500/mo is enough of a social safety net (roughly what current spending levels would support), particularly because of the phasing it in issues. People already have a lot of debt, they already have stupid expectations regarding what they're entitled to.
What I haven't done is compare the current social safety net spending per capita now to what it has been historically, but if the trend is going up then at some point we will pass a reasonable UBI level and then it's just a conversation about how much control the recipients have over the money.
Remember though, the day UBI passes, the poorest among us take a pay cut so the richest among us can get a check. That's going to be a bitter pill to swallow after decades of partisan bickering over how to distribute the resources of an underfunded humanitarian effort. Because what it sounds like is eliminating the means testing from all government assistance.
So while you say the left isn't opposed to UBI, the fact that our current system looks nothing like UBI is as much a result of their class warfare tactics as it is Republicans insistence on conditions for the help related to behavior. Well, that was too strongly stated. The GOP is a little bit assholic on that front, as is anyone who dares want a say in how you spend their money *shakes fist*.