On April 22, 1970, 20 million Americans participated in the first Earth Day, rallying across the country to raise awareness about pressing environmental challenges. Organized by a Democratic senator and a Republican congressman, Earth Day 1970 “achieved a rare political alignment, enlisting support from Republicans and Democrats,” according to Earth Day Network, and provided momentum for the passage of landmark legislation to protect our air, water, and endangered species.

But in today's political climate, even Earth Day has become the target of partisan attacks from the right.

This past Sunday, as millions of Americans celebrated Earth Day, conservative media figures spent the day downplaying the impact of human activity on the environment, advocating for more fossil fuel development, and taking credit for misleading the public about the threat of climate change. Others attempted to spread fear about the holiday by noting that it falls on Vladimir Lenin's birthday, and by linking it to a convicted murderer who falsely claimed to be behind the first Earth Day.

And one right-wing blogger recalled how he tried to delay his son's birth because he “really didn't want a child born on Earth Day.”

It was not long ago that Earth Day -- and the values of conservation and environmental responsibility it represents -- enjoyed bipartisan support. The Times-Picayune reported on Sunday on the shift that has taken place over the last 40 years:

The power and breadth of support for the original Earth Day is hard to imagine today.

“You can't get a Republican politician today to speak on Earth Day, but in 1970, every member of Congress, Republican and Democrat, wanted to speak,” said Adam Rome, an environmental historian at the University of Delaware who is writing a book on the original Earth Day and how it led to sweeping changes and spawned a generation of environmental activists.

Republicans in Washington were among the legislative lions of environmental legislation, but those were days when moderate and even liberal Republicans roamed the Capitol.

Indeed, President Nixon established the Environmental Protection Agency and signed into law the National Environmental Policy Act, the Clean Air Act, and other environmental legislation championed by Republicans. President George H.W. Bush brought us the Clean Air Act Amendments, which strengthened enforcement. And in recent years, Republicans have spoken out in favor of everything from clean energy to efficiency standards to action on climate change.

But since President Obama took office, Republicans in Congress have obstructed climate legislation and relentlessly targeted EPA clean air rules, and the conservative media have seized every opportunity to undermine environmental progress. The reactionary Earth Day commentary is one more reminder of how far right the right has moved.