I dunno, wasn't it Milton Friedman who was promoting UBI during the Nixon administration?
I've got this funny feeling that Congress likes legalistic solutions to problems because they are mostly lawyers. (All lawyers when it comes to Democrats) The pain of filling out paperwork for means testing seems less painful to them than it does to the general population.
The 'swiss cheese' approach to social services is one of the major reasons why U.S. health care is so FUBAR and so hard to fix. Old people have Medicare and they vote -- they don't see there is a problem. Many people get insurance from their employer and might have no idea what their employer pays or how stressful it is for employers to negotiate benefits every year. Veterans have a program, there is Medicaid for really poor people, Medicaid expansion for somewhat poor people, Obamacare exchanges for people who are almost poor, etc.
When you add it all up there is a small pool of people "left behind" and most of those people are transiently uninsured because they'll wind up in some covered category. Balance that against a larger population afraid of losing what they have, and you have gridlock.
