Republican John McCain said Monday that drilling for oil off the US coast is an essential part of any plan to lower gas prices and reduce dependence on foreign sources, and he criticized Democrat Barack Obama for opposing it. "We all know that a comprehensive solution is wind, tide, solar, all the other things all of us believe in," McCain told reporters after touring San Joaquin Facilities Management, an oil company in the California desert that yields 1,100 barrels a day. "In the meantime, as we develop all of these alternate sources of energy, it will be vital that we continue oil production at a high level, including offshore drilling." McCain called Obama the "Dr. No" of energy. But McCain once was too. Just last month, McCain reversed himself after years of opposition and called for lifting the federal ban on oil drilling off the US coast. The Arizona senator promotes energy development as a way to boost the economy, and a recent poll found many voters are open to offshore drilling as a way to ease gasoline prices.