House Republicans approved a sweeping measure on Thursday that would ease rules on banks, weaken consumer protection and scrap federal bailouts for major financial institutions.
"Growth!" US President Donald Trump cheered in a tweet Friday morning.
But Democrats vowed to fight the bill, which few expect to advance further.
"It's fitting that @realDonaldTrump is celebrating a bill that will harm service members, seniors, and families #WrongChoiceAct," Nancy Pelosi, the leader of Democrats in the House, tweeted in reply.
Supporters say the bill, dubbed the Financial CHOICE Act, provides a simpler alternative to the oversight measures known as the Dodd-Frank Act, which passed in the wake of the financial crisis.
Among the major changes, the bill allows banks that maintain a certain level of financial surplus to opt-out of those rules and abolishes the bailout process established for major financial institutions.
It also rolls back a wide range of other rules, touching on issues from payday lending to shareholder proposals.
Congressman Jeb Hensarling, the sponsor of the bill, called it a "better, smarter way".
"It's called the Financial CHOICE Act. It stands for economic growth for all, but bank bailouts for none," he said.
Financial stocks soared after the vote, which some say could push Republicans in the Senate to pursue more aggressive reform.
Senator Sherrod Brown, the Democrat who heads the banking committee in the Senate, has said he is open to loosening rules for smaller community banks.
But he lambasted the House measure, calling it "partisan, dangerous legislation [that] would once again leave families, seniors and service members at the mercy of predatory lenders, and put taxpayers back on the hook to pay for Wall Street's greed and recklessness.
"Democrats have shown we're willing to work with Republicans to tailor the rules where it makes sense, but not if it means killing the reforms that have made the financial system safer and fairer," he said in a statement earlier this week.
No Democrats voted for the House bill on Thursday, which was overshadowed by the testimony from fired FBI director James Comey about the Russia investigation and his interaction with US President Donald Trump.
Many Democrats in the Senate have stayed quiet on the issue.
In an interview with the BBC, former congressman Barney Frank, the architect of the original bill, dismissed the vote as "theatre".
"The very conservative Republicans in the House... this is their show," he said.
