WASHINGTON — Mild-mannered, lawyerly and with a genius for trivia, Richard Cordray is not the sort of guy you picture at the center of Washington’s bitter partisan wars over regulation and consumer safeguards.

But there he is, a 57-year-old Buckeye who friends say prefers his hometown diner to a fancy political reception, testifying in hearing after hearing on Capitol Hill about the agency he leads, the Consumer Financial Protection Bureau. Republicans would like to do away with it — and with him, arguing that the agency should be led by a commission rather than one person.

And with a Republican sweep of Congress and the White House, they may get some or all of what they wish.

Mr. Cordray, a reluctant Washingtonian who has commuted here for six years from Grove City, Ohio, where his wife and twin children live, is the first director of the consumer watchdog agency, which was created in 2010 after Wall Street’s meltdown. By aggressively deploying his small army of workers — he has 1,600 of them — Mr. Cordray has turned the fledgling agency into one of Washington’s most powerful and pugnacious regulators.