Since the topic of the article is Liberalism, I think Obama merits a mention.  If you want, you could delete the adjective "social".  As for your statement that there has been no expansion of the welfare state, I need only mention Bush II's prescription drug plan for seniors and Obama's Affordable Health Care Act.  But social liberalism is not the same as welfare liberalism.  It includes the end of Don't Ask, Don't Tell and the decriminalization of medical marijuana.  The election of a Black president is itself a major victory for social liberalism, in a country where all previous presidents have been White.