WASHINGTON (Reuters) - U.S. Senate Democrats on Thursday failed to pass a measure to block oil and gas drilling in part of the Arctic National Wildlife Reserve, losing to Republicans who believe production  there would provide jobs and wealth.  An amendment blocking the development failed 48-52, mostly along party lines. A lone Republican, Senator Susan Collins of Maine, supported the measure. The only Democrat to vote against it was Joe Manchin from West Virginia. Conservationists and many Democrats treasure the Alaskan reserve, also known as ANWR, as one of the planet’s last paradises. Established by Congress in 1980, it is home to tribes and a habitat for sensitive wildlife including caribou, polar bears and hundreds of species of migratory birds.  Republicans, who now control Congress and the White House, have long wanted to open a portion of ANWR called the 1002 area. Senator Lisa Murkowski, the chair of the Senate energy committee and an Alaskan Republican, called the 1002 portion a “non wilderness area” because the government put it aside decades ago for petroleum exploration. The U.S. Geological Survey estimates the area on the Prudhoe Bay in Northern Alaska has up to 12 billion barrels of recoverable crude.  A Senate budget measure introduced this fall instructed Murkowski’s committee to raise $1 billion over 10 years. She hopes some of that money will come from energy company royalties after opening the 1002 area to drilling. Murkowski urged senators to see the “instruction as an opportunity to do something constructive” and focus on boosting energy output from federal lands that have long been off limit.  The failed amendment, sponsored by Senator Maria Cantwell the top Democrat on the Senate Energy Committee, would have eliminated the directive from the budget resolution seeking to raise funds. Republicans led a “sneak attack” that turned “public lands over to polluters,” Cantwell said. Senator Jeff Merkley, another Democrat, has said there is “something cynical and sad” about the effort to open ANWR because it would boost oil output from the state feeling the fastest effects of climate change, which a majority of scientists link to carbon emissions from the burning of fossil fuels and development.  The battle is not over. The House of Representatives will next have to pass its version of a plan to raise revenues from the drilling. A final budget package would then be worked out by leaders from the two chambers.  Petroleum interests have long lobbied to explore in the area and say technology advances mean the impact of operations in the reserve would be small. Murkowski said oil companies could use infrared cameras to detect and avoid polar bear dens while exploring for oil and gas. It is uncertain whether energy companies that have faced years of static crude prices  amid a wealth of oil in the continental United States would be willing to increase drilling in the harsh and frigid Arctic.  Environmentalists vowed to keep up their fight. “Congress cannot sneak this through the back door when they think nobody is looking,” said Jamie Williams, president of the Wilderness Society. ANWR “is simply too fragile and special to drill, and we have a moral obligation to protect it for future generations of Americans.”  