would the value of gold go up or down in this scenario?

I always get this wrong (even though I do get most things economically at a high level and think that what is emerging is not just terrifying but also fascinating as you can see bigger systemic wheel in motion that only move once every decade or even century

Short answer: yes to gold up. 

Nerd answer: For this pivot to US protectionism to work, I’m kinda in the Luke Gromen/Mel Mattison camp. The dollar will have to be devalued in a big way ultimately to inflate away huge debt load/incentivize domestic industry (ie significant monetary inflation for a while), entailing a major restructuring of US debt (YCC/QE etc). So dollar remains a — but not the only — reserve currency. But US treasuries no longer reserve asset in such a scenario. For the latter, the US/world will likely need a neutral reserve asset like gold and maybe some Bitcoin. Possibly signs of this already happening with gold. 

I could be wrong!