(CNNMoney) — President Obama announced the nomination of his White House chief of staff, Jacob “Jack” Lew, for Treasury Secretary on Thursday. Lew, 57, had been the leading candidate for months, and if confirmed, would be the second Treasury Secretary during the Obama administration. He has overseen budget talks in times of surplus and deficits as a former budget director for Presidents Obama and Clinton. He was also a key player in the 2011 debt ceiling talks, where he earned some criticism from Republicans for his uncompromising attention to detail. Some Republicans and people working on Wall Street have also been concerned about Lew’s lack of business and financial markets experience.