WASHINGTON — The Senate on Thursday blocked President Obama’s nominee to head the Consumer Financial Protection Bureau, as filibustering Republicans who oppose the powers of the new agency successfully challenged one of the administration’s main responses to the financial crisis.

The nominee, Richard Cordray, was rejected after Democrats failed to achieve the 60 votes they needed to move his nomination forward. The vote was 53 yes, 45 no.

President Obama left open the option of a recess appointment, although Republicans have thwarted that tactic recently by staying in rump sessions.

“We are not giving up on this,” he said. “We are going to keep on going at it. We are not going to allow politics as usual on Capitol Hill to stand in the way of American consumers’ being protected.”