Yes, debate.org is generally a conservative website. It is surprising to read the comments on this website and read how conservative our nation truly is. Based on politics you hear from Washington DC and entertainment from Washington, you wouldn't think that's the case, but reading debate.org you can realize how conservative people truly are.
Since Debate.org appears to represent a slice of reality, it's more liberal than conservative. But even with that majority, there is still plenty of room for disagreement and it's seen here on a minute by minute basis. But I also don't think that means the conservative voices here are not welcome, and I have seen many convincing arguments from people on that end of the political spectrum.