If the US replaced all of its welfare and re-distributional programs with a negative income tax (sales/estate/corporate/etc taxes would be scrapped as well), the US would be far less socialist than it is today.

There seems to be reasonable evidence that at least some quantity of 'welfare' is beneficial. If that's the case, then the negative income tax can provide that without all the bad distortions that traditional welfare/re-distributions (SS, unemployment insurance, etc) produce. (Alas, we can never escape the DWL of taxation, though).