Feb. 16 (UPI) -- Vice President Mick Pence administered the oath of office to Mick Mulvaney as the new director of the Office of Management and Budget on Thursday.
The swearing in took place in the evening after the Senate confirmed Mulvaney with a vote of 51-49.
Pence called the former South Carolina congressman "a happy warrior on behalf of fiscal responsibility."
A simple majority was required for Senate confirmation, and the vote was along party lines, with the exception of Sen. John McCain, R-Ariz. McCain, chairman of the Senate Armed Services Committee, said Wednesday his decision to join Democrats in opposing Mulvaney stemmed from Mulvaney's insistence for firm spending limits on the Defense Department.
"I will vote to oppose Congressman Mulvaney's nomination because it would be irresponsible to place the future of the defense budget in the hands of a person with such a record and judgment on national security," McCain said.
Sen. Tim Kaine, D-Va., also opposed the confirmation, citing Mulvaney's positions on defense spending and entitlement reform, as well as his support of a 2013 shutdown of the government instead of a bill to keep the government funded.
Mulvaney's "unwillingness to embrace a bipartisan compromise, even after the government of the United States shut down, troubles me significantly," Kaine said.
Mulvaney's support of changes to Medicare, and the raising of the eligibility age for Social Security, are in opposition to opinions expressed by Trump, who said during the campaign he would protect those programs.