A 54 RAW, I'd say no. It's supposed to be when it'd lower you below 0 or more. Meaning that it assumes you have at least 1 HP and will be taking 1+ damage. But as it was said, it'd be up to the DM.
I'd say yes by RAW for that exact reason. RAI, it's probably not (or at least, it most likely wasn't written with Delay Death in mind). However, let's see what happens if you take damage when at negative hit points (assuming the damage doesn't kill you):
Lowers your hit points? Damage lowers your hit points by definition, so undoubtedly.
Are your new hit points below zero? We're presuming that you're already at negative hit points. As we've established, the damage lowers your hit points. positive numbers or zero can't be lower than negative numbers, so the new hit point total has to be a negative number.
Thus, taking damage while below zero hit points lowers your hit points to below zero. I fail to see the problem.