Santa Barbara County became a symbol of the national environmental movement’s passionate opposition to offshore oil drilling when an oil spill devastated its coastline in 1969. On Tuesday, it became a symbol of the changing national mood as its board of supervisors debated whether to welcome new wells along California’s shores.

The supervisors voted 3 to 2 on Tuesday to end the county’s opposition to offshore drilling, although the vote will have no practical impact on state or federal policies.

But the speed with which opinions have changed in Santa Barbara County as gasoline prices have climbed has been astonishing. The vote there reinforces, at the local level, a shift evident in national polls and in the delicate willingness of Democratic leaders like Senator Barack Obama, the presumptive presidential nominee, and the House speaker, Nancy Pelosi of California, to open the door to limited coastal drilling.

Three weeks ago, the Public Policy Institute of California released a poll showing that 51 percent of Californians now approve of offshore drilling, a 10-point increase in a single year. “I don’t think any of us expected to see the day when there’d be more than 50 percent support for oil drilling,” said Mark Baldassare, the institute’s research director.