1) Like Quora it would have to have widely international participation. But the international anglosphere doesn't share the prejudices that make one "Conservative" in the US. (For example, strong allegiance to Christianity is a conservative given in the US. But not in the UK or Australia. And has a very different meaning in India. Similarly, American Conservatives are (naturally) very concerned with American Patriotism. Another value that's not shared by anyone else in the rest of the world, regardless of political bias.)
2) It would have to be full of curious people. "Intelligence" may not be an exclusively liberal virtue. But curiosity about and enthusiasm for "the other" are liberal.
3) It would be full of tech. people. The Quora community started with Silicon Valley and San Francisco tech. people, and they tend very socially liberal and are politically either liberal or Libertarians.