There is a very strong libertarian argument to be made for a basic income. Assuming that it were implemented in a carefully though out manner (haha, I know), a welfare system centered around a universal basic income would be much less intrusive than the less generous patchwork we currently have. A couple of examples:
- No more corporate minimum wage. There doesn't need to be one, since there is already a basic income. This allows businesses greater freedom in their hiring and pay practices. It allows marginal workers to hold jobs that aren't worth paying $8.50 an hour + payroll tax for, but might be worth paying $6 an hour for.
-No more intrusive questions about marital status, family living arrangements, drug use, etc. The basic income is universal, so we can dispense with having the government making moral judgments about domestic affairs. No more punishing couples for being married or for not being married (our current welfare system somehow manages to do both at the same time).
Additionally, there are very cynical reasons that the elites should support a basic income, which you have already touched on in your post. There is a reason that you thought of France in the early 1800's and not the UK. The UK elites, starting with the Reform Act of 1832, recognized the practical necessity of compromising with the lower classes in order to shore up their own power. No doubt many in power at the time had the French July Revolution (which had overthrown Charles X and established a liberal regime by force just two years earlier) in mind when the Act was passed.
Today, we have a similar situation to that of Europe in the 1800's, although the issue is about economic participation rather than political participation. I hope that we choose as wisely as the British did.