My thoughts on UBI are rather simple. Given the incredible class jealousy, litigiousness and pettiness present in the political spheres, there can be no new program that resembles welfare that could ever be implemented to address structural inequality in the U.S.
But, if UBI is given to EVERYONE, then it could pass and would create a whirlwind of spending... Because poor people are low on everything. Plus, if people can sign-over their UBI to family members for a tax credit, then middle aged Americans can take better care of their elders and children.