For more than 40 years, April 22 has been a day to celebrate and care for our planet. So why would two Sierra Club leaders take the opportunity on this Earth Day to write about democracy?

It’s simple.

Ever since the Supreme Court’s alarming decision in Citizens Unitedin 2010, the same people who’ve been contaminating our air and water with toxic pollution have been contaminating our democracy with toxic money.

Big-polluting, big-money campaign donors are drowning out the voices of everyday Americans. They’re doing it by dumping hundreds of millions of dollars into elections — and warping our government’s priorities in the process.

Mainers can be proud that our state has been on the forefront in the fight against this pernicious trend. In 1996, Maine voters passed the nation’s first clean elections law, which has served as a model for other states around the country. We showed the nation that a system based on small donations from ordinary citizens, coupled with limited public funding, is good for people, good for the environment and good for democracy.

Since then, Mainers who previously could not have afforded to run for office and win have succeeded against the handpicked candidates of deep-pocketed special interests. And with the playing field leveled between big polluters and everyone else, Maine passed significant environmental legislation such as the landmark Maine Climate Change Act in 2003 and Maine’s Kid-Safe Products Law in 2008 — proof that good elections can lead to good policy.

Maine’s Clean Election law has also helped to inspire federal action. The “Government By the People Act,” co-sponsored by Maine Reps. Chellie Pingree and Mike Michaud, would refocus our elections from the wealthy to everyone else. By lifting up the voices of small-dollar donors and amplifying their support through limited public matching dollars, this bill would put everyday voters back in the driver’s seat.

It’s an initiative that is needed now more than ever. Legislative gridlock and obstruction plague Washington, while millions from big-money donors like the Koch brothers subvert our government’s priorities and short-circuit the accountability so crucial to our democracy.

In 2012 alone, the Koch brothers, a pair of oil barons whom many Americans have never heard of, spent over $400 million to influence elections. What followed was a U.S. Congress with one of the worst environmental records in history. Earlier this month, the Supreme Court made this bad situation even worse. In McCutcheon v. FEC,a majority of the court decided to eliminate caps on the amount that big-money donors can spend during a single electoral cycle.

If we want to stop the coal pollution that’s giving our kids asthma attacks, we have to compete against big money. If we want to fight against climate-polluting, toxic tar sands oil, we have to compete against big money. And if we want to end the billions in tax subsidies that Big Oil gets every year, and invest in clean energy instead, then we absolutely have to compete against big money.

Kids with asthma don’t have big checkbooks. Clean air doesn’t have a political action committee. Clean drinking water can’t make contributions to candidates. And nonprofit organizations working to protect the environment can never hope to match the deep pockets of oil and gas companies.

What we do have on our side, though, are people who care about a cleaner, more prosperous future — and legislative solutions that can put us back on track to reaching that future.

Unfortunately, Maine’s ground-breaking Clean Election Act has been weakened by the Supreme Court that brought us Citizens United and McCutcheon. Thankfully, Mainers have risen to the occasion by initiating new legislation that will increase transparency, close loopholes and strengthen Clean Elections. By supporting this initiative, Maine people and leaders will be standing up for the people of Maine — rather than the narrow self-interests of big-money campaign donors.

That’s why the Sierra Club stands proudly with Maine Citizens for Clean Elections and the thousands who are fighting to strengthen our Clean Election Act — not just on Earth Day but every day. Let’s make sure the government of Maine continues to work for Maine people — not polluters.

Michael Brune is the executive director of the Sierra Club. Jim Frick, an Orono resident, serves on the Executive Committee of the Sierra Club’s Maine Chapter.