By Andrew Restuccia and Eliza Collins 

WASHINGTON -- The fate of Neera Tanden's nomination to lead the Office of Management and Budget came down to two centrist senators after another Republican added his name to the list of lawmakers who oppose confirming her.

Republican Sen. Chuck Grassley of Iowa said on Thursday that he would vote against Ms. Tanden. Mr. Grassley, who often votes with other Republicans but has backed many of President Biden's cabinet nominees so far, had not disclosed his position.

The White House is now homing in on Sens. Lisa Murkowski (R., Alaska) and Kyrsten Sinema (D., Ariz.), people involved in the discussions said. A "no" vote from either senator, neither of whom has so far tipped her hand, would doom Ms. Tanden's chances of clearing the Senate.

Executive branch nominations require a majority vote of 51 senators to pass the chamber. Vice President Kamala Harris can break a tie. Because control of the Senate is divided evenly between Democrats and Republicans, even one Democratic defection can throw a nomination into uncertainty.

Democratic Sen. Joe Manchin of West Virginia said last week that he would vote against Ms. Tanden, meaning a Republican would have to break with other members of the party and join the remaining 49 Democrats for the nomination to pass. If Ms. Sinema joins Mr. Manchin in opposing her, Ms. Tanden would need a second Republican to cross party lines, an outcome that Senate aides said was unlikely.

Ms. Murkowski was seen going into Majority Leader Chuck Schumer's office with the New York Democrat Thursday afternoon. She declined to answer questions about Ms. Tanden. Later, Mr. Schumer declined to detail their conversation other than to say it was "about issues that we both care about." Ms. Murkowski told reporters on Wednesday that the White House had been in touch with her about setting up a meeting with Ms. Tanden, to whom she said she had not yet spoken.

The Alaska senator said that, so far, the White House's pitch to her had been: "The president nominated her."

Ms. Tanden has faced criticism from some lawmakers for her past statements on social media while she led a center-left think tank in Washington, which included jabs at senators. She compared Sen. Mitch McConnell (R., Ky.) to Voldemort, the Harry Potter villain; she referred to Sen. Susan Collins of Maine -- a centrist who has backed all of Mr. Biden's nominees besides Ms. Tanden -- as "the worst"; and she said that "vampires have more heart" than Sen. Ted Cruz (R., Texas).

At her confirmation hearings earlier this month, Ms. Tanden apologized for her comments and pledged to be nonpartisan if confirmed to the role by the Senate. Ms. Tanden's supporters accused lawmakers of a double standard, noting that Republicans regularly ignored former President Donald Trump's Twitter comments.

Ms. Murkowski said she learned Wednesday that Ms. Tanden had tweeted that Ms. Murkowski seemed to be "high on your own supply" when the Alaska senator tweeted praise for the 2017 tax bill. "You know, we know, and everyone knows this is all garbage. Just stop," Ms. Tanden said in her tweet.

"I was trying to look at competence, but apparently I'm going to have to do more looking into what she thinks about me," Ms. Murkowski said.

A spokeswoman for Ms. Sinema, who rarely speaks to reporters in the Capitol, said the senator doesn't preview votes.

White House chief of staff Ron Klain said during an interview Wednesday night with MSNBC that he thought the rest of the Senate Democrats, besides Mr. Manchin, would stick together. "I think we'll get Neera confirmed if we can find the Republican vote," he said. "That's what we're working on now. That's what we're trying to get done here."

Mr. Klain said Ms. Tanden would likely receive another job in the administration that doesn't require Senate approval if she is not confirmed to lead OMB.

Sen. Gary Peters (D., Mich.), who chairs the Homeland Security and Governmental Affairs Committee -- one of two panels that postponed preliminary votes on Ms. Tanden's nomination Wednesday -- told reporters Thursday he had no updates.

"We've given our members a little more time to assess her qualifications and her nomination. They just needed more time," he said.

Vermont Sen. Bernie Sanders (I., Vt.), who chairs the Budget Committee, the other panel that delayed a vote, told reporters Wednesday: "There's no secret she's lacking the votes right now and she's working hard to try to get the votes."

The path to confirmation for two other nominees, which had been unknown earlier in the week, seemed clearer by Thursday.

Rep. Deb Haaland (D., N.M.), Mr. Biden's pick to lead the Interior Department, secured Mr. Manchin's backing on Wednesday. He said even though they disagreed on some issues, she had reaffirmed a commitment to working in a bipartisan way. Mr. Manchin, who represents a coal-reliant state, was seen as the most likely Democrat to oppose Ms. Haaland.

Meanwhile, Ms. Collins said Thursday she had a good conversation with California Attorney General Xavier Becerra, the nominee for Health and Human Services secretary, and believed he had done well in his hearing. She hasn't said how she will vote.

Write to Andrew Restuccia at Andrew.Restuccia@wsj.com and Eliza Collins at eliza.collins@wsj.com.

(END) Dow Jones Newswires

February 25, 2021 16:15 ET (21:15 GMT)