The bill, which President Bush called his top domestic priority for 2007, was effectively blocked when the Senate failed to invoke cloture and limit debate on the bill (S-1639) in a 46-53 vote.

This was the second time in June that backers of the legislation were unable to muster the 60 votes needed to surmount conservative Republican and mixed-liberal opposition to the legislation. President Bush, scrambling to salvage the imperiled bill, had called Senators early in the morning to rally support before the crucial test vote.

The immigration bill had been heavily lobbied for by Microsoft and other large technology employers because of clauses that focused on the issue of high-skilled immigration reform. Advocates had hoped that the bill would pass with a provision increasing the number of H-1B temporary work visas available each fiscal year.

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High-tech companies were far from happy with the provisions of an earlier version of the immigration reform bill that also was killed by the Senate. Read more here.

In a statement, Microsoft, based in Redmond, Wash., said it was "disappointed that today's failure by the Senate to invoke cloture will likely result in the collapse of comprehensive immigration reform that is desperately needed to address the shortage of highly skilled talent. This shortfall will limit American competitiveness and technological innovation, hampering not only the technology industry, but our country's leadership in these critical areas."

High-tech companies such as Microsoft argue that a decline in the number of United States-born computer science graduates over the last seven years has forced them to rely on the H-1B visa and employment-based green card programs to deliver adequate supplies of qualified IT and engineer professionals.

"That can only be achieved through immediate reform of these programs to ensure they are meeting the needs of our economy … It is our hope that the Congress will prioritize finding a solution to these urgent issues before the end of the year," said Microsoft officials.

IT worker advocates such as the Washington Alliance of Technology Workers, a tech union, and the Programmers Guild, a tech worker advocacy, vehemently dispute the assertion that there is a shortage of qualified U.S. IT professionals, often pointing to loopholes in the employment systems that leave those systems rife with abuse.

On June 16, the Programmers Guild published on YouTube a video in which an immigration law firm offered advice on how to avoid hiring U.S. workers when a foreign worker is preferred for a position. This set off a firestorm of criticism, drawing the attention and ire of a U.S. senator and congressman, who called it a "blatant disregard for American workers."

The immigration bill included a provision to raise the yearly limit on H-1B visas from 65,000 to 115,000, with a built-in escalator that allowed for up to 185,000 visas, market depending. In 2004, the cap on allotted visas was slashed from a record high of 195,000 to 65,000 per year, causing a heightened fury around H-1B filing time. The H-1B visas supply for the 2007 fiscal year were used up in just over one day.

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