Earlier quoted context omitted.
He donated 400m to funding election infrastructure. How is that donating to Democrats?
There are concerns that they paid for infrastructure in deeply democratic areas and ignored areas that were republican-leaning, in effect making it a Democratic get out the vote initiative. The media doesn't seem too interested in figuring out the actual impact, so I don't think any of us really know if it was balanced or not. But this doesn't strike me as the type of thing we want billionaires doing regardless.
Can you link to something describing the basis for these concerns?