President Obama named former Ohio Attorney General Richard Cordray, right, as the first director of the Consumer Financial Protection Bureau on Monday. In doing so, he passed over Elizabeth Warren, center left. Treasury Secretary Timothy Geithner is also shown at left. (Pablo Martinez Monsivais/AP)

Feisty Harvard law professor Elizabeth Warren has ratcheted up her rhetoric in the two days since the White House announced it would not nominate her to lead the new consumer watchdog agency that she is credited with inventing.

In an interview Tuesday, Warren acknowledged that the political realities of Washington colored her talks with administration officials over who should head the Consumer Financial Protection Bureau, which officially opens for business Thursday. Obama has named Richard Cordray, the former attorney general of Ohio, to the top job.

“The conversations were always in two parts,” Warren said. “One is what works best for the agency, and the other was what was possible given the Republican intransigence on the CFPB.”

Warren said she discussed Cordray as one of several potential nominees in January, shortly after she hired him to become the agency’s director of enforcement. Though Warren does not officially lead the agency, she was tasked with setting it up and hiring staff as a special adviser to the administration. Now, she said she is focused on a smooth transition, and those close to her said she plans to return to Harvard in the fall.

“I haven’t come this far just to bobble the ball now,” Warren said.

She does not seem to be going quietly, however. After attending the White House news conference announcing Cordray’s nomination on Monday, she spent much of the day providing interviews to liberal media, appearing on MSNBC’s Rachel Maddow and holding a conference call with progressive bloggers. At least twice she said she had “rocks” ready to throw at Republicans trying to alter the agency.

Still, Warren said that she does not understand why she has been called a controversial figure in the battle over the CFPB.

“How exactly did I get to be controversial by doing exactly what I thought was the job of standing up the consumer bureau?” she said in an interview.

People close to Warren said she has not ruled out a challenge to Sen. Scott Brown (R-Mass.) next year. Progressive groups have launched a Draft Elizabeth Warren for Senate campaign on Monday that garnered 14,000 signatures within its first five hours and raised more than $19,000. A similar effort to get her appointed as the CFPB’s director garnered hundreds of thousands of signatures.

“After a tough loss, we have to fight even harder — and help Elizabeth Warren get back in the ring,” read an e-mail to members from the Progressive Change Campaign Committee.

If she chose to run, Warren could face a formidable opponent in Brown, whose war chest reportedly totals $9.6 million. Brown won a special election last year to fill the late Edward M. Kennedy’s seat for the remainder of the term.

Boston University professor Fred Bayles, who runs the college’s State House journalism program, said Warren’s name recognition might not carry to her home state.

“You guys in Washington know her very well. But I’m wondering whether or not the rank-and-file voter ... is going to be aware of who she is,” Bayles said.

Monday’s announcement that Warren would not take over the CFPB marks the end of a tumultuous year. In the fall, she was charged with setting up the bureau and hiring its staff, and embarked on a charm offensive to make peace with the financial industry. An analysis by the Sunlight Foundation, a government watchdog group, found that Warren held more than 100 meetings with banks, lobbyists and nonprofit groups on provisions of the financial reform legislation that created the agency. Last week, she sat through a testy four-hour hearing in the House that raised questions about the scope of the CFPB’s authority.

Republicans have insisted that their opposition is not only to Warren but to the structure and funding of the agency itself. On Monday, they held firm to their promise to block any nominee unless the administration agrees to install a five-member commission to run the bureau and increase oversight from other regulatory agencies. They are also seeking to subject the CFPB to the congressional appropriations process, rather than allow it to receive funding from the Federal Reserve.

“It took the president a year to nominate someone to this position,” Senate Minority Leader Mitch McConnell (R-Ky.) said Monday. “I hope he won’t wait that long to address our concerns and bring the CFPB the accountability and transparency it now lacks.”