( CNN ) -- Midway through his presidency , George W. Bush was asked by the journalist John Dickerson to name his biggest mistake since 9/11 and what he 'd learned from it . Here 's what he said : . `` Hmmm ... I wish you 'd have given me this written question ahead of time so I could plan for it . Uhhh ... ( six-second pause ) `` John , I 'm sure historians will look back and say , gosh , he could 've done it better this way or that way . Uhhh ... ( five second pause ) . You know , I just -- uhhh - I 'm sure something will pop into my head here in the midst of this press conference , with all the pressure of trying to come up with answer , but it had n't yet . ... '' Bush then babbled about how he would not have done anything differently in Afghanistan , how Saddam Hussein was a bad guy and how he was confident the truth would come out about weapons of mass destruction ( Well , he was right about that. ) . After filling air and killing time with that nonsense , he tried to return to Dickerson 's question . But Bush 's eyes looked like a slot machine that had just hit BAR-APPLE-LEMON . He said : . `` I hope -- I do n't want to sound like I have made no mistakes . I 'm confident I have . I just have n't -- heh , heh -- you just put me under the spot here , and maybe I 'm not as quick on my feet as I should be in coming up with one . '' ( You can see it for yourself here : http : //www.youtube.com/watch ? v=haQzdW7hg4A ) One of the biggest reasons Barack Obama is president -- and a Nobel Peace Prize winner -- is that he 's not George W. Bush . This week he proved that again . Whereas Bush could n't name a single mistake -- not , say , letting Osama bin Laden escape from Tora Bora , or refusing to allow weapons inspectors to ascertain that Saddam had no weapons of mass destruction , or backing economic policies that took the greatest budget surplus in American history and turned it into the biggest deficit in history -- Obama has stepped up . His statement on Tuesday was close , but no cigar . Refreshingly he acknowledged screw-ups and pledged to get to the bottom of the mistakes and correct them . He said , `` The system has failed in a potentially disastrous way . ... The intelligence community failed to connect those dots . '' That was a good start , but it did n't go far enough for me -- nor , apparently , for our president . Because on Thursday he took full responsibility . `` Ultimately , '' he said , `` the buck stops with me . As president , I have a solemn responsibility to protect our nation and our people , and when the system fails , it is my responsibility . '' Hallelujah ! The president also released a report detailing the failures that allowed a man to very nearly kill 300 people on Christmas Day , he has ordered the government to enhance screening and detection , to increase the use of federal air marshals and to improve the dissemination and integration of intelligence . In short , our president is taking his responsibility to protect us more seriously than his political instinct to protect his own backside . What a change , what a relief , what a difference . In taking responsibility , Barack Obama did the right thing for our country and his presidency . He also showed that a skinny , thoughtful community organizer has a lot more guts than a blustering Ivy Leaguer posing as a cowboy . The opinions expressed in this commentary are solely those of Paul Begala .
President Obama says that George W. Bush could n't be his biggest mistake . He says Bush has never made up for grave errors . He says Obama set a refreshing tone by saying the buck stops with him . Begala : In his responsibility , Obama did right thing for the country .