Through a study of digital composing in LGBTQ+ YouTube reaction video channels, I explore the role of emotion in shaping how writers in virtual communities collectively feel about injustice and write for social change. In the reaction videos, vloggers circulate funny, emotional reactions to anti-LGBTQ+ media undergirded by oppressive ideologies and norms. To guide the analysis, I draw on queer and Black feminist theories to conceptualize "political feeling" as cultural formations of emotions that shape how a community feels toward injustice and open or foreclose possibilities for movement toward social change. By constructing and analyzing composing events situated in a virtual ethnography, I find reaction videos construct and circulate the political feeling of radical joy, or willful and resistant happiness in the face of oppression. Radical joy, then, mediates the satirical critiques of interlocking structures of power and the development of belonging in struggles for liberation in the comment section.