As counterpoint: I've donated to the Great Slate [1], a panel of Democrat long-shots in historically underserved areas. (I'd heard of them in large part thanks to Maciej/idlewords [2])

I've gotten emails, sure, but they respect unsubscribe. From that experience, I'm comfortable donating again through ActBlue [3], the donation platform they used.

[1] https://techsolidarity.org/resources/great_slate.html

[2] related: https://idlewords.com/2019/05/what_i_learned_trying_to_secur...

[3] https://secure.actblue.com/