If Hillary Clinton wants to win the green vote this election, she might have some explaining to do.

While Clinton certainly grasps the science of climate change and has moved to the left on some environmental issues, she willingly accepts campaign contributions from fossil fuel interests.

Greenpeace looked into donations to Clinton from one arm of the dirty-energy sector, oil and gas lobbyists, and found that she has gotten a fair chunk of change from them. Fifty-three lobbyists for the oil and gas industry have made direct contributions to her presidential campaign totaling $126,200. And of those 53, 11 have bundled about $1.1 million to the campaign. This doesn’t include any donations lobbyists made to the super PAC that supports Clinton.

These lobbyists have represented some companies that have, shall we say, less-than-green visions for America, including BP, ExxonMobil, Canadian pipeline firm Enbridge, and Oxbow Carbon, a petcoke company controlled by Bill Koch, estranged brother of Charles and David. Clinton also got donations from lobbyists representing frackers, LNG companies, and the main natural gas industry association.

Last year, when climate activists and The Nation magazine called on all of the presidential candidates to pledge to reject campaign money from fossil fuel interests, Clinton refused. In fact, she’s taken more money from lobbyists in general than any other candidate, including the Republicans.

Now, this doesn’t necessarily mean that Clinton is going to invite Big Oil and Gas to a slumber party in the Lincoln Bedroom should she win the presidency. But as Bernie Sanders — the one candidate who has refused to take money from the fossil fuel industry — surges in the polls, Clinton may at least want to start explaining.