Senator Joe Manchin (D-WV) has said that he would vote against the Biden administration's pick to lead the Office of Management and Budget, Neera Tanden.
"For this reason, I can not support her nomination", Manchin, the most conservative Democrat in the Senate, said in a statement.
Although a final Senate vote on Tanden's nomination has yet been scheduled, Manchin's opposition could scuttle her confirmation because of the Senate's 50-50 split between Republicans and Democrats. The social media remarks have been scrutinized, largely on the right, since her nomination.
In a statement, Manchin said that the "overtly partisan" statements that Tanden had made about lawmakers on both sides of the aisle would have a "toxic and detrimental impact" on her ability to work with Congress in the role. "For this reason, I can not support her nomination", said Manchin, who has a history of breaking with his party. His other nominees - while being processed more slowly than previous Presidents' - have yet to face an existential threat to their confirmations.
Tanden was also grilled by Sen.
"I think we are going to find the votes to get her confirmed", he said.
Manchin explained in a statement that he believes the candidate - Neera Tanden - will not be a unifying force for the US political sphere.
Many Democrats scoffed at such concerns, noting near-unanimous Republican support for former President Donald Trump, who was accused of inciting a deadly attack on the U.S. Capitol partly via inflammatory comments on Twitter and was known for blasting those he saw as opponents - particularly women - as "nasty" or criminals who should be locked up.
During her nomination hearing before the Senate Budget Committee, Tanden was chastised by Chairman Bernie Sanders for her past tweets and she pledged to refrain from making personal attacks such as those she had directed at Sanders in the past.
But the Democratic wins in two Georgia Senate runoffs a month later kept the prospect of her confirmation alive as long as all 50 Democrats voted in favor of her nomination.
Tanden apologized for her past comments during recent confirmation hearings before the Senate Budget Committee and the Senate Homeland Security and Governmental Affairs Committee.
Following reports that she regretted 1,000 tweets, Tanden said she did so 'because I regretted the tone'.
As OMB head she will interact with Senate Budget chair Vermont Sen. There were vicious attacks made against progressives, people who I have worked with, me personally, ' he told her.
'Russia did a lot more to help Bernie than the DNC's random internal e-mails did to help Hillary, ' Tanden wrote, siding with Clinton.
The tweets in question include posts in which she called McConnell "Moscow Mitch" and "Voldemort", called Senator Tom Cotton a fraud, and claimed that compared to Senator Ted Cruz, vampires have more heart.