The claim that "Reality has a well-known liberal bias" was created by Stephen Colbert in the 2006 White House Correspondents' Dinner. The full context was talk

The claim that "Reality has a well-known liberal bias" was created by Stephen Colbert in the 2006 White House Correspondents' Dinner. The full context was talking about Bush's approval ratings: > "Now, I know there are some polls out there saying this man has a 32 percent approval rating. But guys like us, we don't pay attention to the polls. We know that polls are just a collection of statistics that reflect what people are thinking in reality. And reality has a well-known liberal bias ... Sir, pay no attention to the people who say the glass is half empty, [...] because 32 percent means it's two-thirds empty. There's still some liquid in that glass, is my point. But I wouldn't drink it. The last third is usually backwash." It's a tongue-in-cheek way of saying that liberals are more grounded in reality than conservatives.