“The fact that we are here today to debate raising America's debt limit is a sign of leadership failure...Leadership means that ‘the buck stops here.’ Instead, Washington is shifting the burden of bad choices today onto the backs of our children and grandchildren. America has a debt problem and a failure of leadership. Americans deserve better. I therefore intend to oppose the effort to increase America's debt limit.” Senator Barack Obama, March 16, 2006.
More here or here.
And BHO in an April 2011 tv interview: "...that was just a example of a new Senator, you know, making what is a political vote as opposed to doing what was important for the country. And I'm the first one to acknowledge it..."