WASHINGTON — Key Senate Republicans are working to develop a compromise on border security that would satisfy GOP demands for stronger enforcement language in a far-reaching immigration bill without costing Democratic support, lawmakers and aides said Thursday.
To win over skeptical Republicans, senators are considering mandating specific requirements for tools and equipment along the US-Mexico border, instead of leaving it up to the Obama administration, said Senator John McCain, an Arizona Republican who is an author of the bill.
‘‘That may be a way to assuage the concern of some of our friends that are concerned about border security,’’ McCain said. Republican Senator Marco Rubio of Florida, another author, has discussed the same approach.
The talks were underway behind the scenes at the Capitol on Thursday even as the Senate voted 53-47 to defeat an amendment that would have required a controlled border for six months before any immigrant here illegally could take the first steps toward citizenship. It was the first amendment to the White House-backed immigration legislation the Senate voted on.
The outcome suggested that bill supporters have work to do to lock down the 60 votes that will likely be needed to overcome GOP stalling tactics and get it passed in the Senate by July 4, the timeline set by Senate majority leader Harry Reid.
The bill, which would contain the most significant changes to immigration law in decades, would require all employers to check workers’ legal status, allow tens of thousands of new high- and low-skilled workers into the country, and create a 13-year path to citizenship for some 11 million people now here illegally.
The bill also devotes billions to new equipment and personnel along the US-Mexico border, and says the path to citizenship can’t go forward until certain border security requirements are met. But critics say these ‘‘triggers’’ are too weak, and wouldn’t encourage an administration to secure the border.
Rubio has been saying that stronger language on border security would be needed to ensure passage in the Democratic-controlled Senate and the Republican-controlled House. The question now is how to do that without raising concerns among Democrats that the path to citizenship would be delayed — the reason that Senator Chuck Schumer, a New York Democrat, and others gave for opposing the amendment Thursday.
Schumer and the three other Democratic authors of the bill, along with Judiciary Committee chairman Patrick Leahy, a Vermont Democrat, met with President Obama at the White House on Thursday to discuss strategy.
Although a number of Republican senators have their own border security amendments, the hope is to develop a single consensus alternative with as many Republican sponsors as possible. McCain and other bill authors have been working with a number of other Republicans outside their group including Republicans Bob Corker of Tennessee and John Hoeven of North Dakota.