A Bush-era law required us to being moving to more efficient non-incandescent light bulbs which we’ve been doing. The current winner, dropping in price and lasting many years, is the LED bulb.
The incandescent bulbs are largely made on foreign soil and American companies can’t compete.
LED bulbs however are almost all American.
So by rolling back the regulations on the bulb Trump is effectively saying “use more foreign bulbs to make America great!”
I dunno, in the strange mind (if you can call it that) of Trump it probably makes sense.