Actually Bush cut the size of the area for leases in Florida because his brother was up for re election.

http://www.factcheck.org/environmental_groups_ad_distorts_bushs_record_on.html
The Bush administration in 2001 backed off a proposal to allow drilling in the Gulf of Mexico in an area that came as close as 16 miles to beaches in Florida's panhandle. What the Bush administration approved instead keeps drilling at least 100 miles from the coast. But an ad airing in Florida by the League of Conservation Voters gives a different -- and misleading -- impression.
This misleading ad may be a payback for an attack last month by Bush's brother Jeb, who falsely claimed Kerry favors drilling off the Florida coast.

Analysis
Bush's record on Florida offshore drilling is summed up in this Interior Department map: Lease Sale 181 Area
Source: Minerals Management Service, US Dept. of Interior

The area outlined in pink is Lease Sale 181 Area -- a tract of 5.9 million acres first proposed for oil and gas leases in 1997 during the Clinton administration with the actual leasing to begin in December 2001. When Bush took office his Interior Secretary Gail Norton expressed support for going ahead with the sale. But because the extreme northeastern tip of the area reaches to within 16 miles off the coast at a point west of Pensacola, the President's brother Jeb, who was up for re-election as Florida's governor, protested. So the administration retreated, and approved only the smaller area shaded in green. It comes no closer than 100 miles from the Florida coast and, at less than 1.5 million acres, is about one-quarter the size of the original tract.