WASHINGTON — Bickering across a deep divide, supporters of immigration legislation pushed back hard on Wednesday against Republican demands for tougher border security measures before millions living illegally in the country could take the first steps toward US citizenship.
Even modest changes were snared in the political crossfire that erupted on the first full day of debate on the measure, as the two sides failed to agree on terms for voting on seemingly noncontroversial proposals such as granting tribal officials a place on a Border Oversight Task Force.
As drafted, the legislation ‘‘authorizes a permanent legalization program for illegal immigrants regardless of whether the Mexican border is ever secured,’’ said Senator John Cornyn, a Texas Republican. The Senate’s second-ranking leader also wants other measures implemented, including a system to check everyone departing the country that Senator Chuck Schumer, a New York Democrat, said could take a quarter-century to take effect.
‘‘We cannot, should not, and will not tell those who have waited in the shadows for so long that they should wait for 25 years,’’ said Schumer, who was part of a bipartisan group of eight senators who negotiated the bill’s basic provisions and then protected it from major changes in the Judiciary Committee last month.
In addition to taking steps to secure the border and begin a legalization process for millions, the White House-backed legislation would increase the number of visas for highly skilled workers, create a new program for the lesser-skilled to work in the United States, and overturn a family-based system for legal immigration that has been in place for decades.
Senate majority leader Harry Reid, a Nevada Democrat, has said he wants a final vote on the measure before July 4.
Across the Capitol, House Speaker John Boehner, an Ohio Republican, said he hopes immigration legislation can move through committee by then, and be on the floor later in July.
While the obstacles to a final agreement are daunting, the Senate bill has support from both business and organized labor, two groups often at odds.
Additionally, senior Republicans have made it clear they envision the legislation as a way for the party to show a friendlier face to Hispanic voters, who overwhelmingly supported President Obama last fall.
Even some GOP lawmakers who seem unlikely to vote for the Senate bill are recalibrating their rhetoric. One, Senator Rand Paul of Kentucky, said that conservatives could accept a pathway to citizenship as long as the border security measures are tough enough.
‘‘The first part of my plan — border security — must be certified by Border Patrol and an Investigator General and then voted on by Congress to ensure it has been accomplished,’’ he said. ‘‘With this in place, I believe conservatives will accept what needs to come next, an issue that must be addressed: What becomes of the 12 million undocumented workers in the United States?’’