Comprehensive immigration reform cleared a procedural hurdle in the Senate Monday and is on a path to final approval by week's end.

In the first of multiple procedural votes required to get to final passage, 67 senators voted for the "Gang of Eight" immigration package, which included an amendment from Republican Sens. Bob Corker of Tennessee and John Hoeven of North Dakota that tightened border security provisions. The vote total was affected by the absence of some senators who had weather-related flight delays.

The vote tally for final passage of the legislation could look slightly different, but with 15 Republicans joining 52 Democrats to push the bill above the required 60-vote threshold, the "Gang of Eight" package, complete with the Corker-Hoeven "border surge" amendment, looks to be on track to clear the Senate before Congress leaves Washington for the July 4 recess.

That Corker-Hoeven amendment received a positive review from the nonpartisan Congressional Budget Office will likely only serve to solidify support for immigration reform in the chamber. Colorado Sen. Michael Bennet, a member of the "Gang of Eight," said Monday's vote lends credence to the process that produced the legislation.

"It says that committed people working together can actually make progress in this place," Bennet, who chairs the Democratic Senatorial Campaign Committee, told reporters shortly before the vote.

Republicans voting yes included Corker; Hoeven; Sens. Lamar Alexander, of Tennessee; Susan Collins, of Maine; Jeff Flake and John McCain of Arizona; Lindsey Graham, of South Carolina; Orrin Hatch, of Utah; Dean Heller, of Nevada; Mark Kirk, of Illinois; Lisa Murkowski, of Alaska; Marco Rubio, of Florida and Roger Wicker, of Mississippi, although Wicker told reporters he did not intend to support the bill on final passage.

Conservative critics of the package were unbowed, and many took to the Senate floor in the run-up to the vote to denounce the bill and a debate process they argued was unfairly curtailed by Senate Majority Leader Harry Reid, D-Nev.

Ultimately, however, opponents of the legislation are voting against it because they have problems with key policy elements of the bill, from legalizing millions of illegal immigrants to a lack of "triggers" that would measure when the U.S.-Mexico was truly secured before the legalization process could continue.

"It doesn't meet the threshold for border security that I had set," Sen. Richard Burr, R-N.C., said.