In this debate in particular, I think it's critically important to distinguish between "dollars", a currency controlled by the US government, and "wealth", the real things those dollars can buy. As has been pointed out, nobody denies that technically the US can spin up the printing presses and make as many dollars as it wants. However, even ignoring the other catastrophic consequences that would have, there's also the considerations of the real wealth consequences we're committing to. It isn't just "lots of money", it's also things like committing real people to build real facilities so that other real people will take care of the real old people living in those facilities for years at a time on the government's dime. To exaggerate for clarity, we can't afford to have an economy in which everybody is dedicated either to caring for old people, treating old people, or supporting those who do. Somebody's actually got to be able to produce something to feed the economy. Obviously we can't get to this point, but it's not clear how much of our real economy can actually be dedicated to these things, because the support networks can end up being a lot deeper than surface intuition would expect. Studying modern military logistics can be very helpful; in particular, look for the statistics about how many support personnel there are per front-line soldier doing the "actual" military work, and apply the lessons to the "real" economy.