WASHINGTON – The Senate voted to end debate and move toward a vote on an amendment drafted by two Republicans on immigration reform legislation aimed at toughening security measures along the nation’s border.

The vote to proceed on the measure authored by Sen. Bob Corker (R-Tenn.) and Sen. John Hoeven (R-N.D.), opposed by GOP leadership, was 67-27, with 15 Republicans joining 52 Democrats, more than enough to clear the required 60-vote hurdle. Some lawmakers missed the vote because of travel issues.

Republicans joining the two primary sponsors were Sen. Kelly Ayotte of New Hampshire, Sen. Orrin Hatch of Utah, Sen. Roger Wicker of Mississippi, Sen. John McCain of Arizona, Sen. Lamar Alexander of Tennessee, Sen. Jeff Flake of Arizona, Sen. Jeff Chiesa of New Jersey, Sen. Lindsey Graham of South Carolina, Sen. Susan Collins of Maine, Sen. Mark Kirk of Illinois, Sen. Marco Rubio of Florida, Sen. Dean Heller of Nevada, and Sen. Lisa Murkowski of Alaska.

Senate Democratic Leader Harry Reid, of Nevada, now intends to vote on the measure merged with the original Border Security, Economic Opportunity and Immigration Modernization Act of 2013 before the July 4 holiday. Monday’s vote offers a clear indication that the measure, the first major attempt at immigration reform since 1986, will pass easily even though supporters failed to get the 70 votes they targeted.

Under the amendment, five triggers – or goals – must be met before the estimated 11 million illegal immigrants already in the U.S. can start on a pathway toward citizenship, beginning with a form of work visa.

Corker-Hoeven hikes Border Patrol ranks by 20,000 – almost doubling the contingent — and adds 350 miles of border fencing. It spends $4.5 billion on technical innovations intended to provide security personnel with full situational awareness along the southern border. And it implements an entry-exit visa program to keep tabs on visitors who overextend their stay as well as the so-called E-Verify program to make employers aware of a potential worker’s immigration status.

“It specifically spells out those things that have to occur for anyone to move from temporary status to green card status,” Corker said.

The measure received a boost at the last minute from the Congressional Budget Office, which found that the immigration reform bill, with the Corker-Hoeven amendment, will increase border security and strengthen enforcement. The CBO also maintains it will reduce the federal deficit by $192 billion over the next 10 years.

“This is the toughest, strongest, most expensive border provision that we have had,” said Sen. Charles Schumer (D-N.Y.), who is handling the legislation on the floor. “It is augmented by the entry system improvements and mandatory E-Verify. Illegal immigration will drop dramatically.”

Despite the effort at bipartisanship, most Senate Republicans opposed the measure. Senate Republican Leader Mitch McConnell, of Kentucky, who voted against proceeding, expressed concern that “when it comes to the threshold question of border security, today’s assurances may well become tomorrow’s disappointments.”

“It continues to be my hope that we can do something lasting and important about our broken immigration system,” McConnell said. “Living up to our commitments to our constituents, particularly with respect to border security, has long been of critical importance for me. Sadly, I’m not convinced that this amendment solves that problem, and I see no good reason why we would need to vote on it so hastily.”