A Media Diversity Question

They all look like Chuck Todd: The lack of diversity on shows like “Meet the Press” is just embarrassing - Salon.com:

...By House Democratic leadership’s count, there are 78 white men who are Democrats, out of 188 Democratic members in the chamber. This means that white men do not make up a majority of the House Democratic caucus.

So how is it that political press stalwarts, such as the Sunday shows, remain stubbornly white, male and conservative while the rest of the country, and the rest of our politics, moves in the opposite direction?