McCain also lashed out at Mulvaney's efforts on military affairs, including a vote in 2011 that the Arizona senator said would have brought the immediate withdrawal of all US troops from Afghanistan, ending a mission to prevent it from "becoming a safe haven for terrorists".
With Republican Senator John McCain announcing on the Senate floor that he would oppose Mulvaney, Cochran was seen as the potential 51st vote needed in the 100-member chamber for confirmation.
"He said to me in a one-on-one meeting how he would prioritize the debts he would pay if he defaulted on the debt", said Sen. Mick Mulvaney as the new director of the Office of Management and Budget Thursday morning, allowing the budget process to move forward.
"As director of the Office of Management and Budget, Rep. Mulvaney will be at the center of discussions on federal spending and regulations". Susan Collins (R-Maine), were on the fence about Mulvaney's nomination.
Kim Jong-Un's Brother 'Killed By Two Female Spies' In Airport
The report, citing what it called multiple government sources, said the two women hailed a cab and fled immediately afterwards. Jong Nam, estranged from the reclusive North Korean regime, was pronounced dead after being rushed to a hospital.
The close vote came down largely along party lines, although Senator John McCain, R-Ariz., broke with Republicans to vote against Mulvaney.
Thursday was bittersweet for many of congress's most outspoken conservatives.
In 2013, Mulvaney supported shutting down the government for over two weeks in a stalemate with Democrats over funding the affordable Care Act. "And as my colleagues and I sought repeatedly to find legislative solutions to reverse risky defense cuts and eliminate arbitrary defense spending caps, it was Congressman Mulvaney and his allies that repeatedly sought to torpedo these efforts".
"I am hopeful he'll be able to move the needle in the right direction on entitlement reforms, tackling the nation's out-of-control spending and debt problem head on, to secure opportunity and prosperity for current and future generations", she said.