I wrote a short piece on this for Vox, here is one excerpt:
Who is the most influential public intellectual of the last 20 years?
This designation should go to someone who actually has helped change the world, rather than just changing lots of minds. It also should go to someone who has embodied key trends of the time, noting that for both standards I am focusing on the United States.
Based on those standards, I am inclined to pick Andrew Sullivan, who is most recently in the news for his announcement that he is quitting after fifteen years of blogging.
Any discussion of Sullivan’s influence must begin with gay marriage. Thirty-six states and the District of Columbia already have legalized gay marriage, representing a majority of the American population, with possibly Alabama and others to follow. A broader Supreme Court decision for nationwide legalization may be on the way. More generally, gay rights have taken a major leap forward.
…I thought long and hard before selecting Andrew for the designation of most influential public intellectual. Perhaps Paul Krugman has changed more minds, but his agenda hasn’t much changed the world; we haven’t, for instance, gone back to do a bigger fiscal stimulus. Peter Singer led large numbers of people into vegetarianism and veganism and gave those practices philosophic respectability; he is second on my list. A generation ago, I would have picked Milton Friedman, for intellectual leadership in the direction of capitalist and pro-market reforms. But that is now long ago, and the Right has produced no natural successor.
Self-recommending! And again, please note, you should not confuse the designation “most influential” with “the person who, I, the reader, would most like to see elevated in status.” That would be a fallacy of mood affiliation.