Kevin Drum has written a brief piece on Rick Perry to explain why he doesn't think Perry can win the Republican nomination for president. It's also useful as an overview of the less appealing aspects of Perry's politics and character for people not familiar with the Texas governor.
What some may not realize is how extreme Perry is, for example showing no concern at all when he refused to delay the execution of someone very possibly innocent and then shut down the commission investigating the case. Perry has also expressed opposition to Social Security and Medicare, not to mention science, and he's even suggested Texas should perhaps secede from the Union.
Drum mentions that Perry comes across as a narrow-minded religious extremist (he did recently promote an explicitly Evangelical Christian prayer rally, dismissing concerns about violations of the Bill of Rights and the constitution of Texas), but neglects to mention that Perry had previously indicated he wasn't especially religious, before he started toying with the idea of running for the GOP presidential nomination.
Steve Benen has a related post talking about Perry in the context of the radicalization of the Republican base.