Story highlights Katie Walsh, the White House's deputy chief of staff, will join a nonprofit group

Walsh was White House chief of staff Reince Priebus' deputy

(CNN) President Donald Trump on Thursday shook up his senior West Wing staff, days after his administration faced its first major legislative setback in failing to pass a bill to repeal and replace Obamacare.

Katie Walsh, the White House's deputy chief of staff, will join a nonprofit group supporting the President's agenda, the President's top aides said Thursday.

The move marks the second departure of a senior White House official in the first months of the administration, following national security adviser Michael Flynn's forced resignation last month. It also represents a major change in the makeup of the White House's top staff that could shift the power dynamics within the West Wing as Walsh was a close ally of White House chief of staff Reince Priebus.

Walsh was Priebus' deputy, joining him in the administration after serving as his chief of staff when he was chairman of the Republican National Committee.

She is now set to serve as a senior adviser to America First Policies, a nonprofit group helmed by former Trump campaign officials that has struggled to get off the ground in the first months of Trump's presidency.