Try someone's damnedest - Idioms by The Free Dictionary
try (one's) damnedest (redirected from try someone's damnedest)
try (one's) damnedest
To put forth the maximum amount of energy or effort toward some task or goal. Money is a little tight at the moment, but I'll try my damndest to be there for your wedding.
do/try your ˈdamnedest (informal) try very hard; make a very great effort: He was doing his damnedest to make me feel uncomfortable so that I would leave.