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 USA troops from Afghanistan, ending a mission to prevent it from "becoming a safe haven for terrorists".
The South Carolina Republican was narrowly confirmed in a 51-49 vote.
McCain said he generally gives deference and "the benefit of the doubt" to incoming presidents of both parties when it comes to their Cabinets and that "it is with great reluctance" that he is coming out against Mulvaney. Mick Mulvaney as the new director of the Office of Management and Budget Thursday morning, allowing the budget process to move forward.
Immediately after the confirmation of Mulvaney, the Senate will turn to EPA nominee Scott Pruitt, the staunchly conservative Oklahoma attorney general.
House Speaker Paul Ryan, R-Wis., said Mulvaney will "improve the way government does the people's business".
Trump has said that strengthening the military is more important than balancing the budget and is committed to ending budget caps.
SC Man Accused of Planning Attack 'In the Spirit of Dylann Roof'
The prosecution requested a preliminary hearing and detention hearing by held at the same time, Tuesday, February 21 at 2:30 p.m. Around Jan. 25, the document says he posted on Facebook the following statement: "Clean up world jewelry in the name of Yahweh".
Pilot Whales Refloated After Hundreds Stranded on New Zealand Beach
About 1000 whales beached themselves on the Chatham Islands in 1918 and 450 near Auckland in 1985. Volunteers form a human chain to prevent whales from stranding themselves on the beach.
Syria rebels deny receiving invitation to Astana peace talks
The Astana talks are to be followed by a new round of UN-sponsored peace talks in Geneva on February 20. The focus of the talks in Astana is a partial cease-fire that went into effect at the end of December.
President Donald Trump's choice to run the White House budget office has cleared a routine Senate hurdle.
Senator John McCain (R-AZ) speaks to reporters as he arrives for the Republican policy luncheon on Capitol Hill in Washington, U.S., February 14, 2017.
Boccia said she is confident that Mulvaney will work to reform entitlement programs and address government spending.
"In my view, out of control mandatory spending must be addressed to solve our nation's fiscal problems".