The controversy appears to have been kicked off by reports, from outlets including Salon, on new Federal Election Commission filings showing that Musk donated $38,900 to a Political Action Committee named Protect the House. Other contributors to the same fund include NFL owner Robert McNair and casino kingpin Sheldon Adelson, both of whom have made large contributions to President Donald Trump and other Republicans.

Critics have characterized Musk’s contribution as support for a party that opposes much of what he claims to stand for. Above all, the GOP has long been affiliated with attempts to deny the science that predicted climate change, while Musk created an entire company, Tesla, aimed at spreading green-energy technologies.

Musk has been vigorously defending himself against critics, primarily by describing his contributions as aimed at getting access across the political spectrum, not at supporting a Republican agenda.

So that they are willing to listen when I call to object about issues that negatively affect humanity

— Elon Musk (@elonmusk) July 14, 2018

Thanks Jack. To be clear, I am not a conservative. Am registered independent & politically moderate. Doesn’t mean I’m moderate about all issues. Humanitarian issues are extremely important to me & I don’t understand why they are not important to everyone.

— Elon Musk (@elonmusk) July 14, 2018

Musk has also pointed out that characterizations of his contribution have been misleading. The Salon piece described him as “one of the largest donors for a House Republican PAC,” but records show the contribution barely put him in the top 50 for the PAC. Adelson, McNair, and other actual top donors to the fund contributed $371,500 each—nearly 10 times as much as Musk and SpaceX. Further, some detractors may have mistaken the characterization as claiming Musk is a top donor to the Republican party as a whole.

Reports that I am a top donor to GOP are categorically false. I am not a top donor to any political party.

— Elon Musk (@elonmusk) July 15, 2018

The Sierra Club, an environmental advocacy group, has defended Musk against accusations that he isn’t living up to his own P.R.

There have got to be better topics of debate than whether @elonmusk is committed to climate action. He has dedicated his career to the mission of replacing fossil fuels with clean energy & has strongly backed the Sierra Club's advocacy work. We are proud to have his support.

— Sierra Club (@SierraClub) July 15, 2018

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Of course, despite his concerns about the environment and human rights, there are other substantive reasons Musk might want to support Republicans, including their support for tax cuts for the wealthy and limitations on workers’ organizing rights.

Maybe he liked the tax cut.

— Notinmyname (@NastyNana16) July 15, 2018

I'm thinking it's more about them wanting to destroy unions and you agreeing with that.

— #ForAll #COVIDzero 🍞🌹 (@GarrettShorr) July 15, 2018

And the PAC contribution is only part of Musk’s donations to the GOP. As CNBC points out, public records show that Musk and his companies have donated widely to candidates and campaign organizations of both parties, roughly evenly divided between Republicans and Democrats.

Musk’s claim to simply be buying political access with those contributions is itself problematic for many. Some saw it as evidence that the U.S. political system as a whole has become entirely beholden to money, rather than citizens, with large corporations playing an outsized role.

If you are able to put your politics aside, this is actually a very logical statement. It shouldn’t be the case, but sadly in the United States money speaks. Are you going to trash your computer because Intel gave $500k to Trump’s inaugural committee?

— Crypto Craig (@cryptocraig123) July 15, 2018

The vitriol generated by Musk’s contributions can be explained in one word: Trump. Musk has previously expressed opposition to the Trump administration, including publicly opposing Trump’s immigration agenda and resigning from Trump’s tech industry advisory council in June 2017 after Trump’s decision to withdraw from the Paris climate accords. Musk stood in stark contrast to his PayPal cofounder Peter Thiel, who loudly supported the Trump campaign.

But Musk’s contribution to Protect The House significantly undermines that stance. The group is specifically aimed at preserving a Republican majority in the House of Representatives in the upcoming midterm elections, against a predicted “Blue Wave” that could put Democrats in control. Winning a majority in the House would allow Democrats to push back at least somewhat against Trump administration policies, as well as potentially ramping up investigations into allegations of corruption by the Trump campaign, White House staffers, and the president himself.