Many 501 (c) 3’s have added "Action Funds" or PACS or another corporation using the same name with a couple of extra words trading off their nonprofit name and most people don’t know the difference. Is it legal yes, fair no. You might think you are giving money that is tax deductible but find out later you can’t. Tobacco Free Kids is a good example they have two corporations: The Tobacco-Free Kids Action Fund is a non-partisan 501(c)(4) nonprofit organization affiliated with, but separate from the Campaign for; Tobacco-Free Kids, a 501(c)(3) nonprofit.
It is all in the fine print, pay attention to who you donate to and for what.