For states like Louisiana, Texas, Mississippi and others, its a large portion of their work force. If unemployment is 10% now, it will only get worse (possibly quadruple) by placing a moratorium on drilling!
Furthermore, we need the oil!
Buying oil from countries that hate us has allowed for the largest transfer of wealth in the history of civilization. If we drilled, unemployment would go down, economy would grow stronger and energy independence could be obtainable.