Mnuchin will make America work for Wall Street, Sen. Jeff Merkley says

Sen. Jeff Merkley slammed Donald Trump's selection of Steve Mnuchin for Treasury secretary on Wednesday.

"This man is an expert on how to make money in predatory lending and putting him in charge — it is absolutely the opposite of draining the swamp. It is filling the swamp with a swamp monster No. 1 who is an expert on how to take it to low-income families," Merkley said Wednesday on CNBC's "Squawk Alley." "It really is the opposite of what Trump said he was going to do."

The Trump transition team and Mnuchin did not immediately respond to CNBC's request for comment on Merkley's remarks.

Mnuchin, who was finance chairman for Trump's presidential campaign, is a Wall Street veteran, having spent 17 years at Goldman Sachs. His impending nomination seems at odds with Trump's populist campaign rhetoric for downtrodden blue-collar workers.

Some are concerned that Mnuchin would roll back regulations that were drafted in the wake of the Great Recession, such as the Dodd-Frank Act. The former banking executive told CNBC on Wednesday morning that stripping parts of Dodd-Frank "will be the No. 1 priority on the regulatory side." Such legislation was passed with the goal of protecting consumers and preventing another collapse of a major financial institution like Lehman Brothers.

"If you want somebody to dismantle the protections for consumers, he's just the guy to do it," said Merkley, D-Ore., who serves on the Senate Banking, Housing and Urban Affairs Committee.

Earlier Wednesday, Trump transition spokesman Jason Miller said that the president-elect has assembled a "Cabinet of winners" and that Wilbur Ross and Mnuchin can fix the system because they understand it so well.

"There's nobody better to understand how the tax code works, to understand how our trade policies work, to understand just how American workers have been treated unfairly in recent years, and what's needed to go on that people who have actually helped to save companies and create jobs, like Wilbur Ross and Mnuchin," Miller said on a call with reporters.

Miller also touted Mnuchin as a "world-class financier," noting the former banker played a key role in developing Trump's tax reform plan.

— CNBC's Jacob Pramuk and NBC News contributed to this report.