Treasury Secretary Steven Mnuchin Win McNamee/Getty Images Steven Mnuchin was confirmed by the US Senate on Monday night as the new secretary of the Treasury.

Mnuchin's confirmation came down nearly on a party-line vote of 53 to 47, with no Republicans voting against the confirmation.

Democratic Sen. Joe Manchin of West Virginia voted for Mnuchin. Manchin was also the only Democrat to vote for Attorney General Jeff Sessions' confirmation.

Mnuchin, a former Goldman Sachs banker and hedge fund manager, came under fire during his confirmation for various mistakes in financial disclosures to the Senate, as well as several previous investments.

Mnuchin's fund invested in a mortgage lender called IndyMac at the height of the housing crisis (the name was later changed to OneWest). The lender's subsequent foreclosures on homeowners was called out by opponents as proof that the Treasury nominee profited from the financial woes of everyday Americans. Democrats claimed Mnuchin's company used tactics such as robo-signing to foreclose on as many people as possible. Some Republicans even called out the lending practices at OneWest.

Mnuchin contended that his firm invested in IndyMac/OneWest after the company had already developed a large amount of bad loans and government regulation prevented him from preventing more foreclosures.

Additionally, Mnuchin failed to disclose roughly $100 million in assets — mostly real estate — and a series of offshore entities in his first financial disclosures, correcting the error just hours before his confirmation hearing. Democrats said this was evidence of Mnuchin lying, while the Treasury pick said it was a simple clerical error.

Republicans have advocated for Mnuchin based on his financial services experience and saying Democrats objections were not sufficient to block the nomination.

The questions regarding the foreclosure practices and disclosures led the Democrats on the Senate Finance Committee to boycott a vote on Mnuchin's and newly confirmed Secretary of Health and Human Services Tom Price's advancement to the full Senate.

Republicans suspended the standing rules of the committee the next day to advance the nominations without a single Democrat casting a vote.

Senate Democrats continued to decry Mnuchin's nominations during debate on Monday, but did not have the votes to block the nomination.

Mnuchin has downplayed some of Trump's more aggressive rhetoric on economic issues such as trade, instead focusing squarely on the need to simplify and decrease US taxes and regulation.

During his confirmation hearing he also said there may be a need for a "21st Century version" of the Glass-Steagall Act, referring to the bill that separated commercial and investment banks and was repealed in the late 1999.