Mr. Trump expressed his pride upon selecting Mr. Mulvaney as head of the budget system, saying that with his aid, they can take care of the over $20 trillion debt the United States is now in, and he will professionally and wisely manage future spending so as to salvage the nation from "drowning in red ink".
Members of the caucus turned to social media to share their excitement about Mulvaney's selection.
Ryan, who served with Mulvaney on the House budget committee, returned the favor on Saturday.
For those still fretting over how much Trump may honor the wishes of the conservatives who make up his base - particularly the fiscal conservatives - it's hard to see any of us being too upset about this pick. With the choice, Trump now has four Cabinet-ranking jobs to fill, from Agriculture secretary and secretary of Veterans Affairs to two more economics-related posts: chair of the Council of Economic Advisers and USA trade representative. This is the person who will be steering the budget proposal negotiations for Trump and if you were hoping for a budget cutting, small government conservative in that slot, you probably won't do much better than Congressman Mick Mulvaney of SC. "He has been a conservative reformer from day one, proposing solutions to fix the budget process and our regulatory system". "Whether it is his distinguished military service or highly impressive track record in the world of business, Vinnie has proved throughout his life that he knows how to be a leader and deliver major results in the face of any challenge".
Donald Trump 'Thank You Tour' Rally in Mobile
Aides said the president-elect probably would spend Christmas week there and could remain at the Florida resort until New Year's. At the end of the night, he joked that he offered to buy the Clinton campaign's fireworks "for five cents on the dollar".
"Mick is a great choice for OMB director", U.S. Sen.
"Mulvaney was not an early Trump backer during the presidential campaign", South Carolina's The State newspaper notes.
"Mulvaney brings a wealth of experience on economic, budgetary and fiscal issues to his new role", the transition said in a statement, calling the Indiand Land congressman "a strong voice in Congress for reining in out-of-control spending, fighting government waste and enacting tax policies that will allow working Americans to thrive". In November, Trump selected Haley to be the U.S. Ambassador to the United Nations.
But Mulvaney will also benefit from the long list of former U.S. House Republicans who have since become senators, who can vouch for Mulvaney having worked with him directly. He's held his Congressional seat since 2011. Tim Scott, R-Charleston, said in a statement.
Emma Dumain is The Post and Courier's Washington correspondent.