Past environmental disasters have prompted major U.S. laws, but the worst oil spill in U.S. history has yet to break the Senate logjam over the pending energy-climate bill.

Why the difference?

"People's outrage is focused on BP," Anthony Leiserowitz, a researcher at Yale University who tracks public opinion on climate change, tells The Washington Post in story today. The spill "hasn't been automatically connected to some sense that there's something more fundamental wrong with our relationship with the natural world."

Environmentalists want the public to see the Gulf of Mexico oil spill, begun April 20 and still spewing, as reason to lessen U.S. dependence on fossil fuel and support a Senate bill by Sens. John Kerry, D-Mass., and Joe Lieberman, I-Conn., to reduce greenhouse gas emissions.

They've held "Hands Across the Sand" events at Gulf beaches to protest offshore drilling, and in Washington, they spelled out "Freedom From Oil" on the National Mall with American flags, reports the Post.

Yet the Senate remains gridlocked in an election year rife with anti-incumbent fervor and Americans, in public opinion polls, still put economic concerns far ahead of environmental ones. With gas prices down from a year ago, more are driving this summer, reports AAA.

In contrast, a much smaller oil spill in 1968 (100,000 barrels) near Santa Barbara, Calif., along with a fire on Cleveland's Cuyahoga River, helped create the first Earth Day in 1970 and the U.S. Environmental Protection Agency months later.

Readers: Has the Gulf spill changed your views about fossil fuels?