WASHINGTON - The Senate on Thursday confirmed President Donald Trump’s nominee to lead the Consumer Financial Protection Bureau, ushering in business-friendly leadership for a polarizing watchdog agency long detested by Republicans and the banking industry.

The chamber voted 50 to 49, along party lines, in favor of Kathy Kraninger’s nomination.

Kraninger will replace the bureau’s acting director, Mick Mulvaney, who is also the White House budget chief and Kraninger’s current boss. Her nomination took much of Washington by surprise. Kraninger, the associate director of general government at the Office of Management and Budget, has no experience in consumer finance but now will become one of the country’s most powerful banking regulators.

The CFPB was born in response to the global financial crisis to police the way banks manage mortgages, credit cards, payday loans and other financial products. Republicans, many of whom opposed the creation of the agency, have complained for years that during the Obama administration the bureau was too aggressive, taking extreme steps to go after companies and demanding exorbitant financial penalties. Democrats have defended the CFPB, noting its success in the collection of billions in fines and regulating a complicated mix of companies.

In just a year as its acting director, Mulvaney has overseen a stark retrenchment of the agency. Publicly announced enforcement actions have dropped about 75 percent from average in recent years, while consumer complaints have risen to new highs, according to a Washington Post analysis of bureau data. Kraninger is expected to continue Mulvaney’s efforts to curtail the CFPB’s powers.

Republicans have praised the White House’s choice of Kraninger, arguing that her management experience made her a good choice for an agency.

“I am confident that with her experience and knowledge of budget management, Kathy will excel as Director of the Bureau,” Rep. Jeb Hensarling, R-Texas, chairman of the House Financial Services Committee and one of the CFPB’s fiercest critics, said in a statement.

The Consumer Bankers Association, a trade group that includes Bank of America and Wells Fargo, congratulated Kraninger, noting in a statement from its president that she will have “the final say over virtually every financial institution in the country as well as almost every financial decision Americans make.”

But without a deep understanding of the history and complexity of consumer finance, Kraninger could become a puppet for influential financial groups, Democrats and consumer groups who oppose her nomination have argued. Sen. Elizabeth Warren, D-Mass., who helped set up the CFPB, called the choice of a Kraninger “another punch in the gut to America’s hard-working families.”