Votes on Neera Tanden nomination to OMB postponed amid bipartisan opposition

President Joe Biden's embattled nominee Office of Management and Budget Director, Neera Tanden, faced another set back in her confirmation battle Wednesday morning, with a vote on her nomination in the Homeland Security Committee postponed "because members need more time to consider the nominee," a Democratic committee aide said in a statement.

"The president deserves to have a team in place that he wants, and we're going to work with our members to figure out the best path forward," the aide continued.

The Senate Budget Committee also delayed a confirmation hearing, two sources with knowledge of the matter told ABC News.

While the delay underscores the continued trouble surrounding Tanden's nomination, White House press secretary Jen Psaki tweeted Wednesday morning the administration was not planning to pull the nomination.

"Neera Tanden is a leading policy expert who brings critical qualifications to the table during this time of unprecedented crisis," Paski tweeted. "She has a broad spectrum of support, ranging from the U.S. Chamber of Commerce to labor unions, and has a strong record of working with both parties that we expect to grow in President Biden's cabinet as the first South Asian woman to lead OMB."

Biden, while seeming to acknowledge it would take some effort, said Tuesday that he still saw a path forward for Tanden, despite bipartisan pushback that has thrown her hopes for confirmation into question.

"We're going to push. I still think there's a shot -- a good shot," Biden told reporters Tuesday afternoon, echoing Psaki, who said that it was the White House's expectation that Tanden would be confirmed earlier that day.

Tanden's confirmation came into question Friday, when Sen. Joe Manchin, D-W.Va., announced that he would break with his party and vote against Tanden's nomination, citing past tweets with strong language critical of Republican members of Congress and Sen. Bernie Sanders, I-Vt., many of which were deleted prior to her nomination.

Since then, the list of moderate Republicans opposing Tanden for the role has continued to grow. Still, Psaki told reporters during Tuesday's briefing the White House is not considering pulling the nomination, which could be the first of his to fail without 50 votes in the Senate.

"There's one candidate to lead the budget department, her name is Neera Tanden," Psaki said.

She went on to outline Tanden's outreach ahead of the Senate confirmation vote, saying Biden's nominee has had 44 meetings with senators of both parties, 15 of which have happened since Friday.

"She's committed to rolling up her sleeves, having those conversations, answering questions as they come up, reiterating her commitment to working with people across the aisle," Psaki said.

The White House was also working behind the scenes to help get Tanden's confirmation across the finish line, Psaki said, telling reporters Monday that they were "working the phones," to reach out to Democrats and Republicans alike on Tanden's behalf.

But it's not clear who exactly the White House is targeting in the outreach efforts, after several moderate Republicans seen as possible swing votes said that they had not spoken with the administration about Tanden's nomination.

A GOP aide told ABC News on Monday that Sen. Susan Collins, R-Maine, had not spoken to either the White House or Tanden about the nomination battle, and Sen. Rob Portman, R-Ohio, a former OMB director himself, told reporters that the nominee did not even come up in any of his recent discussions with the administration despite the appointee's fate hanging by a thread.

Both senators said they did not plan to vote for Tanden.

"Neera Tanden has neither the experience nor the temperament to lead this critical agency. Her past actions have demonstrated exactly the kind of animosity that President Biden has pledged to transcend," Collins said in a statement.

Portman announced his opposition Monday afternoon, saying in a statement, "the tone, the content, and the aggressive partisanship of some of Ms. Tanden's public statements will make it more difficult for her to work effectively with both parties in this role."

Sen. Mitt Romney, R-Utah, also announced his plans to vote against Tanden's confirmation, which appears to leave her success or failure in the hands of a lone Republican senator, Lisa Murkowski.

The senator from Alaska told ABC News on Monday that she too had not spoken with the White House about Tanden and was still mulling over her decision.

When pressed if the White House had made an effort to reach out specifically to the group of moderate Republicans, Psaki demurred.

"People here are working the phones, and we're just not going to provide day-by-day updates on exactly each senator and office that we've communicated with, but they can communicate on their own, of course, if they've been reached out to or -- you know -- or what communication they've had," she said.

Murkowski said Wednesday that she's since spoken to the White House but remains undecided as she still has a lot of "homework" left to do -- especially after she was alerted to a tweet from Tanden that was critical of her.

"I suggested to the White House that my colleagues were being very critical of the statements and rightly so I think some of them were clearly over the top," Murkowski said. "It seems that in this world we've kind of gotten numb to derogatory tweets. I don't think that's a model that we want to send to anybody."

Sanders, who heads the Budget Committee, was candid about the decision to postpone the vote.

"I think there's no secret she's lacking the votes right now and she's working hard to try to get the votes," he said.

Sen. John Kennedy, R-La., painted a bleak picture of Tanden's prospects.

"I'm not saying she's a smoked turkey but the smoker is heating up," Kennedy said Wednesday. "It's not just her tweets its what those tweets manifest."

"I think there is concern by both Republicans and Democrats that she will be overtly political and that her allegiance is not to America and it's not to President Biden it is to Secretary (Hillary) Clinton," he added.

If confirmed, Tanden would be the first woman of color to serve as OMB director.

Several groups reiterated their support for Tanden despite the narrow path, including the Congressional Asian Pacific American Caucus, which sent a letter to all 100 senators reaffirming their support for Tanden Monday.

Top Democrats have also criticized Republicans' objections to Tanden over her Twitter use as a double standard in light of former President Donald Trump's use of the social media platform during his time in office.

"For Republicans who looked the other way with the nastiest of tweets from their president, their leader -- to now say Neera Tanden can't get in because of her tweets is a little bit of a contradiction," said Senate Majority Leader Chuck Schumer.

Sen. Elizabeth Warren, D-Mass., also stood by Tanden.

"The idea that the Republicans are going to complain about someone that has sharp elbows on Twitter is pretty outrageous," Warren said Wednesday.

ABC News' Benjamin Siegel and Sarah Kolinovsky contributed to this report.