‘Marg’ also means ‘demise’ and ‘damage’ as it isn’t an english word. Point being we have a word that doesn’t directly translate.

A translation would still remain ‘Down with Israel’ in that phrase.

Which conveniently demonstrates, right out the gate, that the official translation is 'Down With America".

The direct translation also means something like ‘Down with America’. Word choice matters when translating for a target audience.