Elon Musk, SpaceX, and Tesla have a long history of donating to both Republican and Democratic politicians and PACs. But the news that Musk recently donated $38,900 to Protect the House, a PAC working to keep Republicans in control of Congress has raised eyebrows: If Musk truly believes that burning fossil fuels is “the dumbest experiment in history, by far,” he should explain why he continues to support a political party that still largely believes climate change doesn’t exist.

In recent election cycles, Musk has avoided talking too much about specific political candidates, even though he has made donations to Hillary Clinton, Barack Obama, and a series of Republican and Democratic congressional candidates. But the donation to Protect the House and a $33,900 donation last year to the National Republican Congressional Committee from SpaceX and Tesla are larger sums of money than he donated to Democratic politicians in recent years, according to Open Secrets (it is possible not all of Musk's political donations are included in its numbers.)

The question, then, is whether Musk’s donation to Protect the House represents any fundamental shift in his politics, and, if he cares about climate change so much, why is he spending money to protect Republican political power?

Musk has at every turn talked about about how important reversing climate change is to him. At the opening of the the Tesla Gigafactory in 2016, for instance, Musk started his speech by saying that “the Gigafactory is about making enough electric cars and stationary battery packs that it actually moves the needle from a global carbon production perspective, so that it does really change the world.”

From a global carbon perspective, the Gigafactory and Tesla have not yet moved the needle. What has moved the needle, in a negative way, is the Republican party’s systematic and cynical rollbacks of policies designed to slow climate change.

Donald Trump pulled the United States out of the Paris climate agreement; the EPA, under now-ousted secretary Scott Pruitt, has enacted policies that are friendly to fossil fuel companies and has tried to roll back Obama-era climate policies; Ryan Zinke’s Department of the Interior wants to allow more oil drilling offshore and on public lands. A Republican-controlled Congress has failed to pass any meaningful legislation that would force America to deal with climate change. There are 53 climate change deniers in the Senate and 232 climate change deniers in the House, the vast majority of them are Republicans.

I do believe that Musk does think climate change is an existential threat and wants to drastically reduce carbon emissions, but in writing a check to Protect the House, Musk does not get to pick the Republican policies he likes and ignore the others; he is supporting the party that gleefully advances fossil fuel interests and puts its head in the sand on climate.

I think it's too early to call Musk a hypocrite on climate change—he has long supported a carbon tax, resigned from Trump's business advisory panel when the United States left the Paris Agreement, and besides being a business pursuit, Tesla has demonstrated a model for clean energy moving forward. But I do think it's time for Musk to explain how his thoughts on climate change coexist with his support of the Republican Party. I've reached out to Musk and will update the story if I hear back.