Cases abound of U.S. presidents stumbling into major failures when information that could have prevented the wrong decision was available. Examples include the attempt to free hostages from Iran by President Jimmy Carter, the missed intelligence warnings ahead of the 9/11 terrorist attacks by President George W. Bush and more recently, difficulties implementing the website for the Affordable Care Act insurance policies under President Obama. Elaine C. Kamarck , a senior fellow at the Brookings Institution, looks at ways to sidestep such failures and also at how presidents can recover from them, if they should occur, to be effective leaders. She discussed her ideas, based on her book titled  Why Presidents Fail and How They Can Succeed Again  on the Knowledge at Wharton show on Wharton Business Radio on SiriusXM channel 111 . (Listen to the podcast at the top of this page.) Below is an edited transcript of the discussion.…