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Washington — Negotiations in the Senate to forge a bipartisan compromise on U.S. immigration and border policy failed to gain enough traction to pass before the end of this session of Congress, dooming yet another effort to reform a system that has not been updated in decades, congressional officials familiar with the matter told CBS News.

Sen. Kyrsten Sinema of Arizona, an independent who until last week was a Democrat, and GOP Sen. Thom Tillis of North Carolina had been discussing a potential deal that would have included the legalization of a subset of the millions of unauthorized immigrants living in the U.S., as well as certain measures aimed at reducing illegal crossings along the U.S.-Mexico border.

But Sinema and Tillis did not strike a deal that would have been able to secure the necessary 60 votes in the evenly divided Senate during the lame-duck session, three congressional officials said, requesting anonymity to describe the outcome of internal negotiations.

The long-shot bid marks Congress’ latest failure to pass a law designed to overhaul an immigration system it has not significantly updated since the 1990s and that Democratic and Republican lawmakers have said is in desperate need of reform.

The failure to reach a deal during the lame-duck session also dampens prospects of a bipartisan agreement on immigration in the near future, since Republican lawmakers will take control of the House in January and have vowed not to grant “amnesty” to any group of unauthorized immigrants.

Sens. Kyrsten Sinema and Thom Tillis leave the Senate chamber on Feb. 25, 2020.

J. Scott Applewhite / AP

One of the congressional aides familiar with the talks said there wasn’t enough time for Sinema and Tillis to reach a deal before the end of the year, especially given ongoing efforts to pass government funding bills. The aide said a framework stemming from the talks could serve as the basis for a bill in the next Congress.

In an interview with Politico last week, Sinema said she and Tillis were working on the “most difficult political issue of all of our careers.”

The talks between Sinema and Tillis focused on providing a path to permanent legal status to “Dreamers,” or unauthorized immigrants brought to the U.S. as children, a longtime Democratic priority. They also sought to address Republican concerns about the unprecedented levels of border arrivals recorded over the past year.

According to people familiar with the negotiations, the border-related items floated as part of the talks included increasing the salaries of Border Patrol agents and bolstering their ranks, providing additional funds to the Department of Homeland Security for detention facilities and deportations and enacting additional penalties for migrants who do not attend their court hearings.

Other proposals included the establishment of processing centers to determine whether migrants have credible asylum cases and an extension of the Title 42 pandemic-related border restrictions, which have allowed the U.S. to expel hundreds of thousands of migrants on public health grounds since 2020. The policy, which blocks migrants from seeking asylum, is set to end on Dec. 21 because of a court ruling.

While the talks between Sinema and Tillis received expressions of support from moderate lawmakers and organizations, they also garnered criticism from critics on both the left and right. 

Immigration hardliners and some Republican lawmakers criticized the legalization proposal for Dreamers, saying the U.S. should not be granting “amnesty” to immigrants living in the U.S. without legal permission amid record arrivals of migrants along the southern border.

Progressive advocates and lawmakers, on the other hand, denounced the border-related proposals, including the Title 42 extension, saying they would undermine the rights of asylum-seekers.

Republican Sen. John Cornyn of Texas, who has previously floated bipartisan immigration compromises, told Reuters this week that the Sinema-Tillis talks were “not going anywhere.”

For decades, Congress has remained gridlocked on immigration issues, with major bipartisan efforts to change U.S. immigrations laws faltering in 2018, 2013 and 2007. The first bill to legalize Dreamers, for example, was introduced over two decades ago, in 2001.