I am so confident that that is untrue, I don't even feel the need to link studies; questioning whether the American voting public supports SS and Medicare is like questioning if they oppose slavery or endorse family values & apple pie. An extraordinary claim in need of extraordinary evidence, for sure.
And, sadly, I won't take "Trump won the election and then put Elon in charge of cutting stuff, so clearly Americans support that decision" as evidence instead of direct, scientific surveys. For one thing, much less than half of the voting public voted affirmatively for Trump; for another, I hope we can all agree that people on all sides very often vote for reasons very loosely related to the candidate's actual positions on policy.
Apologies if I'm rude, really grateful that such convos are happening on HN in the first place! Separate from "would we be better off with or without the New Deal welfare state and/or the entire federal government", I think this is an appropriate place to agree on empirical facts about the current situation. And "that idea is extremely unpopular" is such a fact, IMHO.