A vote to bring the so-called border security amendment to the Senate floor for debate passed easily on Monday night, clearing the way for a cloture vote on the entire reform measure scheduled for Thursday:

The Hill:

The Senate voted Monday to advance a border security amendment to bipartisan immigration legislation, building momentum for a final vote later this week.

The vote stood at 66-26 at 6:30 Monday evening and was being held open to allow more senators to return to Washington to vote. 

Fourteen of the yes votes were Republicans, suggesting supporters could hit the 70-vote threshold they hope to reach in the final vote. It is thought a big, bipartisan vote could put pressure in the GOP-held House, where immigration reform faces dimmer prospects.

Senate GOP Leader Mitch McConnell (Ky.) and Sen. Rob Portman (Ohio) were among the notable Republican no votes. 

The amendment boosting security spending by $30 billion was intended to address persistent GOP concerns about a porous U.S.-Mexico border, and could give political cover for many Republicans to vote for the final bill.

The amendment sponsored by Sens. Bob Corker (R-Tenn.) and John Hoeven (R-N.D.) authorizes increasing the number of border patrol agents by 20,000 and constructing 700 miles of fencing.

It adds $38 billion in spending for security measures to the $8 billion previously included in the base bill. At a minimum, it requires the implementation of $4.5 billion worth of technology and equipment to achieve full surveillance of the border.

Sen. John McCain (Ariz.), the chief Republican sponsor of the broader bill who helped negotiate the deal with Corker and Hoeven, said it would ensure a 90-percent apprehension rate of illegal entrants along the southern border.

"The head of the border patrol has said unequivocally to me that if you get this technological equipment in that he is confident that we will have 90-percent effective control of the border and 100-percent situational awareness," he said.