U.S. Chief of Staff--as important as in "The West Wing"?

In last night’s episode of “The West Wing”, a character referred to the Chief of Staff as “the virtual co-president”. In the show, that’s how Leo McGarry is treated–he’s involved in every important meeting and decision. The vice president, however, is hardly ever seen, and rarely involved in the decision making process.

I realize “The West Wing” is just a T.V. show, but how close does this mirror real-life?

Is Andrew Card the second most powerful man in the country?

Also, is he involved in more meetings and decisions than Dick Cheney?

Yes, and yes.

White House Chief of Staff