Ohio State University did a study on The Colbert Report and found something very interesting.

Additionally, there was no significant difference between the groups in thinking Colbert was funny, but conservatives were more likely to report that Colbert only pretends to be joking and genuinely meant what he said while liberals were more likely to report that Colbert used satire and was not serious when offering political statements.

Conservatism also significantly predicted perceptions that Colbert disliked liberalism. Finally, a post hoc analysis revealed that perceptions of Colbert's political opinions fully mediated the relationship between political ideology and individual-level opinion.

As the Political Wire put it: Many Conservatives Don't Think Colbert is Joking

I guess they really do live in an alternate reality.