supply side says lowering taxes creates demand. Supply side would typically like to see taxes cut for the consumers and tax payers as well as the elite.
Trickle down seems to imply giving breaks to the elite and letting their consumption and investment decisions do all the heavy lifting for the economy.
They both might work but I would argue broad based well targeted tax cuts would do the most good in most situations. Especially when the elite now make world wide decisions and spend a lot of money buying politicians for an advantage rather than improving products and competing.
True tax cut is aimed to create demand. A good point.
I seriously think Trump will bring better economy. US has the world's largest debt primarily because of huge trade deficit. Trade deficit is caused by companies doing outsourcing. e.g. Apple, Nike etc
Imposing tariff on these companies will make them cut off their foreign labours but this is not a concern to US govt. It will be interesting to see whether tariff will lead to higher inflation which could offset tax cut