In a significant political upset, Sens. Kyrsten Sinema and Joe Manchin voted against President Biden’s nominee for the National Labor Relations Board, sparking a wave of criticism from many in the party with which they caucus.

The lawmakers' dissent led to the failed confirmation of Lauren McFerran, deeply frustrating Senate Democrats, as The Hill reports.

Senators Break from Party Lines

On Wednesday, Sinema (I-AZ) and Manchin (I-WV), both registered as independents, cast their votes against the five-year nomination of McFerran to the National Labor Relations Board.

This unexpected move resulted in a 49-51 vote, blocking what would have been a narrow approval.

Senate Democrats were visibly upset by the outcome, as Sinema and Manchin's decision undermined a key appointment supported by the administration. Their "no" votes handed Republicans a significant procedural victory, impacting the balance of the board tasked with labor disputes and rights.

Both senators, having distanced themselves from the Democrat caucus -- Manchin in May and Sinema last December -- have previously clashed with the party on several major issues, creating a backdrop of tension and anticipation leading up to the vote.

Democratic Responses Range from Relief to Resentment

Reactions among Senate Democrats ranged from disappointment to outright anger. Sen. Bernie Sanders (I-VT) labeled the action "pathetic," reflecting a sense of betrayal felt by many. Sen. Tina Smith (D-MN) expressed her frustration, noting the importance of maintaining a balanced board, which now remains an unresolved issue.

Sen. Elizabeth Warren (D-MA) commented on the broader implications of the vote, stating, "Millions of working people across the country will pay the price for their actions." This sentiment echoed a widespread concern among Democrats that the decision would have lasting negative impacts on labor rights and regulations.

Despite the criticism, some Democrats expressed a sense of relief regarding the impending departure of both senators from the Senate next year, highlighting the friction their independent stances caused within the party.

Manchin and Sinema Defend Their Decisions

Manchin defended his decision, emphasizing that his vote was not a matter of partisanship but of principle. "If it makes sense, I do it. If it doesn’t make sense, I don’t do it," Manchin stated, justifying his position as grounded in reason rather than party loyalty.

Meanwhile, discussions around Sinema's vote involved more personal critiques. An anonymous Democrat senator accused her of "pure unadulterated selfishness," suggesting her decisions were often self-serving. This stark accusation highlights the personal tensions that have bubbled up due to her voting record.

Another anonymous senator suggested the votes against McFerran by Sinema and Manchin felt like a "parting shot," a final act of defiance against their former caucus, which had supported them through various legislative battles.

Bipartisan Legacy and Future Uncertainties

Despite their often-contentious relationship with the Democratic Party, both Sinema and Manchin have been instrumental in passing significant bipartisan legislation during President Biden’s term.

Their roles were pivotal in several major bills, demonstrating their ability to cross party lines effectively.

However, their latest actions cast a shadow over their legacies, as they prepare to exit the Senate. The decision to oppose McFerran's nomination is seen by many as indicative of their increasingly unpredictable and isolated political paths.

As the Senate looks ahead, the dynamics within the Democratic Party caucus are poised for a shift.

With the departure of Sinema and Manchin, the party faces both a challenge and an opportunity to unify its members ahead of further legislative endeavors.