What's it like having a memory that doesn't go back more than four years? Obama did not wreck the economy. It was already a complete shambles when he took office. It did a total face-plant starting in August, 2008, three months before the election (and the writing had been on the wall for at least two years prior to that). Obama has not "fixed the economy", but it's better now than it was when he took office.
Bush's major contribution to the economy had been to cut taxes while starting two major wars, a mistake no previous President had ever made. His wars turned much of the world against us, and his budgetary blunders put us on the road to fiscal catastrophe. Obama, unfortunately, has not found a better road.