Bill Cosby compares Obama to Sisyphus rolling rock up the hill

Famed actor and comedian Bill Cosby on Thursday said people who are critical of President Obama are "acting like they have no idea what he inherited" at the White House. 

Cosby compared the first four years of Obama's presidency to the Greek myth of Sisyphus, the king condemned to an eternity of rolling a rock up a hill only to have it fall back down to the bottom.

"I see Obama as Sisyphus in the first four years. And nobody would speak about the size of the rock, or the elevation of the hill. All you hear people talk about is what he didn’t do," said Cosby on MSNBC's online show "Press Pass" with David Gregory.

"He tried to bring us together. Even to argue with radio hosts, and people who have nothing to do with anything; it’s important that this man has had to fight similar battles of a black person in a position in America. Hundreds of thousands and millions of people still behind him, but people who are very quietly acting like they have no idea what he inherited. It’s as if he had the surplus, when he moved into office," he added. 

Cosby was appearing on "Press Pass" to promote the reopening of the historic Howard Theatre in Washington, D.C. 

The television icon also weighed in the controversial shooting death of Trayvon Martin, saying the incident raises issues about the proliferation of guns in the United States.

"It's about the gun. It's about this gun," said Cosby, gesturing to indicate the weapon. "Guns in our country."

George Zimmerman, the man who allegedly shot and killed African-American teenager Martin, was charged Wednesday with second-degree murder, opening the latest chapter in a case that has become a proxy for national controversies over gun rights and racial tension.

"It's the gun that, whether it's legal or not, outside of the house, patrolling around — it is not necessary. This is a country that should behave better in terms of putting guns in the hands of people, unless they have been qualified," he added.