ABC News' Z. Byron Wolf: Even as a giant oil slick heads for land and states of emergency have been declared along the Gulf Coast, Sen. Mary Landrieu, D-Louisiana, came to the Senate floor defending offshore oil drilling. Sen. Bill Nelson, her Democratic colleague from Florida, called today for a halt to President Obama’s plan to expand offshore drilling until an investigation into the Deep Water Horizon explosion can be completed. Landrieu disagrees. “We must continue to drill,” she said. She has compared the disaster in the Gulf to two previous disasters – the nuclear meltdown at three mile island and also the Challenger space shuttle explosion. In the case of three mile island, she said, the US essentially shut down its nuclear program and now is worse off for it – behind the French and others in nuclear energy, dependent on foreign oil. She also brought up the Challenger explosion. But as a counterpoint to three mile island. “What we did not do is end the space program. We did not stop launching. We did not stop exploring,” she said. “We have to find a way to make sure it never happens again, strengthen our resolve and… continue to be the world leader,” she said of offshore drilling. “I am not saying that to minimize this disaster… There may be those who need to be held accountable,” said Landrieu, but she argued that offshore drilling leads to less pollution than other actives. “We don’t think that burying our head in the sand and pretending that our country doesn’t need this energy is the way to go,” she said.UPDATE: Democrats and Republicans are supposed to be debating the Wall Street Reform bill on the Senate floor, but there has been more debate today among Democrats on offshore oil drilling.No sooner had Landrieu wrapped her speech defending offshore drilling than Sen. Bob Menendez took to the floor to rebut her.”I’m deeply concerned that the current five year plan recently announced by the administration would allow oil drilling less than 5 miles from Cap May, New Jersey,” he said.Menendez said the threat of an oil slick on the Atlantic coast is “Not just an environmental threat, but an economic one as well.”"It simply does not make sense to play Russian roulette,” he said, with the coastal economies of New Jersey, Delaware and Maryland. ”It is a wakeup call for all of us,” he said. Menendez asked President Obama to reconsider his five year plan, which includes drilling off the Atlantic Coast, Alaska and the Eastern Gulf of Mexico.