Sen. Kyrsten Sinema of Arizona and Sen. Joe Manchin of West Virginia voted Tuesday not to confirm President Joe Biden’s renomination of Lauren McFerran to serve on the National Labor Relations Board. The no vote from the two independents, both of whom chose not to seek re-election in 2024, will block further control of the labor regulator by Democrats – their former party with whom they still caucus – and pave the way for President-elect Donald Trump’s next administration strips workers’ rights while pursuing an anti-union agenda.

McFerran is the current chairman and one of three Democrats on the NLRB, which is the federal agency that enforces labor law. Normally, the board consists of five members, each nominated by the incumbent president for a five-year term. However, there are currently only four, including one Republican. Shortening McFerran’s term allows the GOP to gain a three-way majority rather than maintaining a Democratic edge through 2026.

Sinema, who had not cast a vote in the Senate since Thanksgiving, appeared to deliberately side with the Republicans against McFerran’s appointment, with Manchin then arriving too late and delivering the decisive blow for a final tally of 49 yes votes and 50 yes votes against. Had he not shown up, Vice President Kamala Harris likely would have voted to keep McFerran on track for another term on the NLRB. House Democrats and independent Sen. Bernie Sanders had called on outgoing Senate Majority Leader Chuck Schumer to do everything he could to ensure Democrats maintained the balance of power in the body.

This is not the first time that Manchin and Sinema have joined forces to thwart Senate Democrats’ plans. Most infamously, in 2022, they joined Republicans in rejecting a proposed one-time change to the filibuster that would have cleared the way for two major voting rights bills. The law was aimed at ensuring free and fair elections after Trump’s lies about election theft in 2020 led Republican politicians and officials nationwide to crack down on voter access.

Both senators have also failed to support workers’ rights and bow to corporate interests. Manchin, who has made millions over the years from Enersystems, his family’s coal waste brokerage firm, had previously allied with Republicans to block progressive labor reform that would hold large companies like McDonald’s responsible for working conditions imposed by their franchisees or subcontractors would have been liable. He also effectively gutted the Build Back Better Act, which included a provision to penalize companies that prevent employees from organizing. Sinema also rejected this and once sensationally voted against an increase in the minimum wage.

It’s unclear what Manchin plans to do after his term ends in January, but he was president of Enersystems before entering politics and could return to the energy industry. His successor on the Hill will be West Virginia Gov. Jim Justice, a Republican. Sinema, who is set to be replaced by Democrat Ruben Gallego, reportedly once told Sen. Mitt Romney that she could “do anything” after leaving office, declaring, “I can go on any committee I want.” I can be a college president.” A Sinema aide suggested that this personal conversation, reported in a 2023 political biography of Romney, had been “misinterpreted.”

Still, the policy positions they took in the Senate have positioned Sinema and Manchin to capitalize on corporate opportunities, like many former conservative Democratic lawmakers who were a thorn in their party’s side before becoming lobbyists or consultants. After all, both senators have done a lot to protect the profits of wealthy executives — while ensuring that they can continue to exploit low-wage workers.