The Obama administration is proposing to open vast expanses of water along the Atlantic coastline, the eastern Gulf of Mexico and the north coast of Alaska to oil and natural gas drilling, much of it for the first time, officials said Tuesday.The proposal — a compromise that will please oil companies and domestic drilling advocates but anger some residents of affected states and many environmental organizations — would end a longstanding moratorium on oil exploration along the East Coast from the northern tip of Delaware to the central coast of Florida, covering 167 million acres of ocean. Under the plan, the coastline from New Jersey northward would remain closed to all oil and gas activity. So would the Pacific Coast, from Mexico to the Canadian border.