You’re being myopic or extremely pessimistic.
Myopic because Trump only has 3.5 years left as president, and we see how quickly he folds as soon as the stock market takes a hit: he already capitulated to China. This is the thing he ran on twice, bringing jobs back to America and he more or less abandoned that project the moment he decided to lower tariffs on china. So the market will continue as it has until neoliberalism implodes for real instead of this false start.
Or pessimistic, because you believe that Trump will fuck up so bad that the SP500 will be worthless in 3 years. In which case, I would not invest in stock at all and would buy ammo, guns, stockpile food and build a shelter because a cataclysmic scenario is the only thing that could cause that.
Remember SP500 is for long term investment, so when thinking about it you need to think not of what’s happening today but what will happen in 5+ years. If I was evaluating this, I would have stockpiled cash last year and would have spent this year buying the dips.