This week, "Sesame Street" kicks off its fortieth season on air. But the TV show's transition to middle age hasn't been entirely smooth. Conservative bloggers are blasting an episode in which Oscar the Grouch, who lives in a garbage can, described the fictional "Pox News" channel as "trashy." (Presumably he would know.) And the show has flirted with politics before: Politicians guest-star, and international versions of it cover topics like HIV in South Africa and ethnic strife in Ramallah. Click through this TNR slideshow to see videos of political figures who have visited Elmo, Big Bird, and the rest of the “Sunny Days” gang.