The Valdez spill slaughtered hundreds of thousands of sea birds, otters, fish, and other wildlife; the Gulf coast is home to even more wildlife than resided in Prince William Sound where the Valdez spill occurred. So even more dead birds will appear on the front pages' of local newspapers. The location of the spill also makes it far more likely that this spill will be in the public eye, rather than sequestered off in some remote Alaskan locale, as was Exxon Valdez. The location also makes it possible that parts of the Mississippi river will have to be closed off, causing more public outrage.
The spill has already pressured Obama to rescind his expansion of offshore drilling. A supermajority of people will now believe that oil drilling is a grave risk, despite hundreds of other rigs operating without any problems, and billions of gallons of oil being pumped from U.S. shored with no problems at all. The oil industry is one of the most heavily regulated industries in all of America, and spills are anomalies. But the public is easily swayed by disasters like this, and that will be the last thing on their minds.
Unfortunately, abandoning our planned expansion of oil drilling now will only make us more reliant on Mexican and Saudi Arabian oil, and pose a greater risk to our national security. That means, in the most practical sense, that there's going to have to be a new way to defend more oil expansion. People are going to think "offshore drilling" and not think of how expensive their gas bill are, but instead think of a dead sea animal on a Louisiana shore. Louisiana is also on federal aid, having been declared a state of emergency. That means a whole new variety of issues will crop up with the U.S. government failing to help the Pelican State.