Audacious Epigone documents this for politics by figuring out the demographics of the London Daily Telegraph's list of the 100 most influential American liberals and 100 most influential American conservatives. Who's on the list and in what order they appear is arguable (that's one purpose of these lists -- to generate arguments).
But these kind of lists are very useful for advancing demographic understanding because they typically are developed for other purposes than to advocate a particularly point about demography. They don't have to be all that accurate to give a reasonable picture of elite demographics.
So, what we find is that whites and males still dominate on both sides of the ideological divide:
|Average Age||58 years, 7 months||Just under 58 years|