Green’s Dictionary of Slang

up for the downstroke phr.

(US black) committed to action.

Parliament ‘Chocolate City’ [lyrics] You don't need the bullet when you got the ballot / Are you up for the downstroke, cc?
[US]P. Beatty White Boy Shuffle 121: I would shout a perfunctory ‘Heeeyyy!’ showing the clubgoers that I was up for the downstroke and that at any at any moment there might be a ‘partay ovah heah’.