On Friday, President Joe Biden signed legislation meant to force an agreement between rail companies and unions in an effort to prevent a nationwide rail strike. Despite claiming he would be "the most pro-union president you've ever seen", Biden is moving to impose an agreement on workers that they already voted down.

In September, eight of the rail unions agreed to a settlement that established the largest raises for rail workers in four decades. However, the offer left out key issues for workers specifically paid sick leave. As a result, four unions rejected the offer, introducing the possibility of a strike. The remaining unions have since confirmed that they would not cross picket lines if a strike occurs.

According to the rail companies' industry group, Association of American Railroads (AAR), a nationwide rail work stoppage would cost the U.S. economy up to $2 billion per day.

Soon, Biden began calling upon Congress to act, and less than two weeks after the unions set a strike date, the House voted in favor of legislation to impose the September agreement on all of the unions. During the process, Republican lawmakers blocked efforts requiring companies to provide family leave and sick days.

"I negotiated a contract no one else could negotiate," Biden told reporters in response to questions about why he wasn't pushing for sick leave. "What was negotiated was so much better than anything they ever had."

This legislation is a rare display of the Constitution's commerce clause. Under this clause, Congress can step in to prevent a national rail worker strike in order to prevent the economic damage that such a disruption could cause.

"A strike of that magnitude would have a painful impact on our economy and that is an unacceptable scenario as inflation continues to squeeze West Virginians and Americans heading into the holiday season," said West Virginia's Democratic Senator, Joe Manchin.

The commerce clause hasn't been used this way since the 90s, but it's hardly an obscure law. While Democrats usually prefer to let companies and unions work things out on their own, House Speaker Nancy Pelosi said it was "with great reluctance" that she was recommending Congress override the union negotiation process.

Pelosi pushed for paid sick leave to be included in the bill but ultimately failed to drum up the support needed, and the Senate soundly rejected similar efforts. Proposals to extend the negotiation period were also voted down. In the end, the only version of the bill that received approval from Congress was one that enforces the previously rejected agreement.

According to union leaders, the rail companies could easily afford to offer paid sick leave to their workers.

"Without a doubt, there is more to be done to further address our employees' work-life balance concerns, AAR CEO Ian Jefferies said, "but it is clear this agreement maintains rail's place among the best jobs in our nation."

With lawmakers blocking any improvements to rail worker benefits, this vote is a major blow to the ongoing union push being seen across the U.S. labor force. To organizers, the meaning is clear: lawmakers will turn against workers if the threat to their employer's bottom line is significant enough.

"The Senate just failed to pass seven days of paid sick leave for rail workers. We are grateful to the 52 Senators who voted YES and stood with rail workers," the Transportation Trades Department labor coalition tweeted, referencing the Representatives who voted in favor of giving workers sick leave. "Shame on the 43 elected leaders who abandoned the working class. We will not forget it."

In the end, the bill enforcing the September agreement passed in the Senate, 15 to 80. The group that voted against the proposal is made up of an unusual mix of people, including both progressive Democrat Elizabeth Warren and ultra-Conservative Josh Hawley of Missouri. Hawley was also one of the few Republicans who supported paid leave.

"If DC Republicans want to be a working class party, they might want to do something for workers," Hawley tweeted.