From NBC's Courtney Kube
A senior U.S. official confirms that there is evidence today of fracturing and growing fissures within the leadership of the Egyptian government.
"There is a debate going on inside the inner circle" of the Egyptian leadership, the official said.
The official declined to speculate whether the members of that "inner circle" are influential enough and the fracturing strong enough to force President Mubarak to step down, saying only that "it's just not sustainable."
The official added that even without the rumblings within the government, the situation in Egypt is not economically sustainable. As the protests continue, "the economy continues to grind down," the official said.