To open the Arctic National Wildlife Refuge in Alaska to oil and gas drilling, President Bush will have to change the minds of seven Republican senators who are on the record as opposed to drilling. Last year, proponents of drilling won a symbolic 51-49 vote. In the fall election, however, anti-drilling forces gained seats, and the votes would now seem to line up as 54 against drilling and 46 in favor of drilling. Sen. Bob Smith (R-N.H.), chair of the Senate Environmental and Public Works Committee, is among those Republicans who oppose drilling. The others are Susan Collins and Olympia Snow of Maine, James Jeffords of Vermont, Lincoln Chafee of Rhode Island, Peter Fitzgerald of Illinois, and Richard Lugar of Indiana.