(WASHINGTON POST) — White House Chief of Staff William Daley resigned Monday, a year after taking the job, shaking up White House management as President Obama gears up for his tough reelection campaign.

During a brief appearance at the White House, Obama announced that Daley, 63, will be replaced by Budget Director Jacob Lew, effective at the end of the month. Daley will stay on until then to help ease the transition through the president’s State of the Union address Jan. 24.

Daley, a longtime banker and former Commerce secretary, never seemed comfortable in his current job during a difficult political year for Obama, whose protracted and bitter legislative battles with Congress helped dragged down his public approval ratings.

The chief of staff struggled to develop relations with legislators in both chambers on Capitol Hill, and his future in the White House was cast into doubt late last year after reports that he had relinquished day-to-day operations to senior adviser Pete Rouse.

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