Congress hasn’t historically been where progressives secure protections for same-sex marriage. 

The political battle largely played out in individual states. And it was the Supreme Court that ultimately legalized gay marriage nationwide, allowing Congress to avoid ever passing a law codifying the practice in all 50 states. The few times Congress has spoken on the issue have usually been to limit gay marriage, such as the 1996 Defense of Marriage Act defining marriage as a union between a man and a woman and outlining states’ rights to not recognize same-sex nuptials.

But now bipartisan duo Sens. Tammy Baldwin and Susan Collins hope to reach a legislative conclusion to the on-again, off-again debate in the next couple of weeks. They’re working to convince enough Republicans to support federal legal protections for gay marriages. Despite a 50-50 Senate, a fiercely divided political climate, and concerns about the bill’s religious liberty implications, they’re optimistic they can.

They spent the week reaching out to GOP senators and working on tweaks to the bill, titled the Respect for Marriage Act, but senators still left town Thursday afternoon without the 10 Republican supporters required for it to overcome a filibuster. Time is short, with a vote expected this month.