Marc Piasecki via Getty Images; Stefani Reynolds/AFP via Getty Images
- Melinda French Gates endorsed President Joe Biden on Thursday and Elon Musk isn't happy about it.
- "Might be the downfall of Western civilization," the mercurial billionaire said in response.
- Back in March, Musk criticized another billionaire's ex-wife, MacKenzie Scott, for her charity work.
Melinda French Gates has given her first-ever presidential endorsement, and Elon Musk isn't too happy about it.