Republicans' Immigration Bill Blocked by Senate Democrats Democrats in the Senate on Wednesday blocked consideration of a bill Republicans passed last week in the House of Representatives that would give 55,000 permanent resident visas to foreigners graduating from American universities with advanced degrees in science or technology. The bill, which passed the House on Friday, was opposed by most Democrats. It would have given the resident visas, known as green cards, to immigrants who obtained master's or doctoral degrees in the so-called STEM fields, science, technology, engineering and mathematics. To avoid increasing the overall number of visas available each year, the measure would free up existing visas by abolishing an annual lottery that distributes green cards to foreigners from countries with traditionally low immigration to the United States. Senator John Cornyn, a Republican from Texas, sought unanimous consent to bring up the bill. But Senator Charles E. Schumer of New York, a Democrat who is chairman of the Judiciary subcommittee on immigration, objected. He said Democrats were in favor of providing more visas for the graduates. "But what we don't do is take away other visas," Mr. Schumer said. The outcome was expected. Republicans had approved the STEM bill to show that they are willing to act on measures to fix the immigration system. The issue became newly important after the presidential election, in which Latino and immigrant voters, a fast-growing part of the electorate, gave their support overwhelmingly to President Obama. Passing the bill in the Senate "would be a signal to the American people that we can work together to enact needed immigration reforms," said Senator Charles Grassley, a Republican from Iowa. Democrats argued that the diversity lottery, as it is officially known, gives permanent residency to many immigrants from Africa and Eastern Europe who would otherwise be excluded.