WASHINGTON (AP) — Far-reaching immigration legislation cruised toward passage in the Senate as House Republicans pushed ahead Wednesday on a different approach that cracks down on millions living in the United States illegally rather than offering them a chance at citizenship.

Presidential politics took a more prominent role in a long-running national debate as Sen. Marco Rubio, R-Fla., tried to reassure conservatives that many of the criticisms of the bill, which he helped write, are “just not true.”

The potential 2016 White House contender said in remarks on the Senate floor it has been difficult for him “to hear the worry and the anxiety and the growing anger in the voices of so many people who helped me get elected to the Senate and who I agree with on virtually every other issue.”

The political impact of the issue aside, there was no doubt that the Senate bill was on track for passage by Thursday or Friday.

Supporters posted 67 votes or more on each of three procedural tests Wednesday, far more than the 60 needed to prevail. More than a dozen Republicans sided with Democrats on each, assuring bipartisan support that the bill's backers hope will change minds in the House.

At its core, the legislation includes numerous steps to prevent future illegal immigration, while at the same time it offers a chance at citizenship for millions living in the country illegally.

It provides for 20,000 new Border Patrol agents, requires the completion of 700 miles of fencing and requires an array of high-tech devices be deployed to secure the border with Mexico.

Businesses would be required to check on the legal status of prospective employees. The government would be ordered to install a high-tech system to check on the comings and goings of foreigners at selected international airport in the United States.

Other provisions would expand the number of visas for highly skilled workers relied upon by the technology industry. A separate program would be established for lower-skilled workers, and farm workers would be admitted under a temporary program.

Some farm workers who are in the country illegally can qualify for a green card, which bestows permanent residency status, in five years.

Many of the bill's supporters also cheered a ruling from the Supreme Court that said married gay couples are entitled to the same federal benefits as heterosexual couples. The decision would allow gay married citizens or permanent residents to sponsor their foreign-born spouses for U.S. residency, and Homeland Security Secretary Janet Napolitano pledged to implement it.

The basic legislation was drafted by four Democrats and four Republicans who met privately for months to produce a rare bipartisan compromise in a polarized Senate. They fended off unwanted changes in the Senate Judiciary Committee, and then were involved in negotiations with Republican Sens. John Hoeven of North Dakota and Bob Corker of Tennessee on a package of tougher border security provisions that swelled support among Republicans.