President Obama today announced that White House Chief of Staff Bill Daley is resigning after a year on the job to return to his family in their hometown of Chicago. Office of Management and Budget Director Jack Lew will succeed Daley as Obama's top aide. 

Daley offered his letter of resignation the same day Obama returned from his Hawaiian vacation last week, but the president did not initially accept, asking Daley to take additional time to think about it instead. 

"But in the end, the pull of the hometown we both love … was too great," Obama said as he stood between Daley and Lew in the White House State Dining Room. "Bill told me that he wanted to spend more time with his family, especially his grandchildren, and he felt it was the right decision."

"Bill has been an outstanding chief of staff during one of the busiest and most consequential years of my administration," the president said. "No one in my administration has had to make more important decisions more quickly than Bill.  And that's why I think this decision was difficult for me." 

With the State of the Union just two weeks away and the president heading into a tough re-election battle, the changing of the guard comes at an awkward time for the White House. 

"There is no question that I'm going to deeply miss having Bill by my side here at the White House.  But as he will soon find out, Chicago is only a phone call away and I'm going to be using that phone number quite a bit.  I plan to continue to seek Bill's advice and counsel on a whole range of issues in the months and years to come," Obama said.

Daley, the son and brother of Chicago mayors, will take on a new role as a co-chair of the president's re-election campaign. 

Lew assumes Daley's responsibilities after serving as the head of the OMB for more than a year. "As anyone who's been following the news lately can tell you, this is not an easy job," Obama said. "Over the last year, he has helped strengthen our economy and streamline the government at a time when we need to do everything we can to keep our recovery going

"I have every confidence that Jack will make sure that we don't miss a beat and continue to do everything we can to strengthen our economy and the middle class and keep the American people safe," the president said.