(Credit: Esteban Felix/AP Photo)

Vice President Joe Biden today assured a group of campaign donors in Wisconsin that Republican criticism of President Obama's leadership style doesn't match up with what he's witnessed firsthand.

"I've watched him make decisions that would make another man or woman's hair curl," Biden told the crowd of 150 inside the Italian Community Center in Milwaukee, according to a pool reporter on scene.

Biden, who has said he's the last man in the room with Obama before a tough call, often attests that his boss has a "backbone like a ramrod."

And today he said that mettle - and the "serious problems" Obama faced upon taking office - put the president in a class of his own.

"I think I can say … no president, and I would argue in the 20th century and including now the 21st century, has had as many serious problems which are cases of first-instance laid on his table," Biden said. "Franklin Roosevelt faced more dire consequences, but in a bizarre way it was more straightforward."

The vice president claimed that the complexity of the 2008 financial crisis presented challenges in a way the Great Depression of 80 years ago did not.

Biden also discussed the decision by Obama to authorize a covert raid into Pakistan to kill or capture Osama bin Laden, noting that nearly the entire national security team - including Biden - advised against the raid. Obama made the call anyway.

The only one on the team who agreed with the president, said Biden, was then-CIA director Leon Panetta.

"Nobody but one person in that entire apparatus said go," Biden said.