In addition to happily accepting direct donations they usually have an auction up of some sort of donated comics related stuff so you might snag a collectible AND help support free speech.
"The Comic Book Legal Defense Fund was founded in 1986 as a 501 (c) 3 non-profit organization dedicated to the preservation of First Amendment rights for members of the comics community."
They do this by helping provide lawyers to defendants in court cases and lobbying against laws that restrict free speech.
Browse through these articles to get a taste of the sort of things going on around the country right now.
Of particular interest they recently helped get an internet censorship law suspended in South Carolina.
Go ahead and donate if you've got it to spare and educate yourself either way.