Roll back the bankruptcy laws to pre-2005 to reduce the cost of risk.
I remember growing up outside of the US learning quite explicitly that one of the geniuses of the American system, a key factor in its dramatic success compared to other countries, and a competitive advantage, was its bankruptcy system that allowed people to try things; put in best efforts; but in the worst case scenario get a fresh start.
Getting rid of that was insane and I worry about its long term consequences. US entrepreneurs already face additional risks versus their overseas counterparts - like lack of a healthcare system not tied to employers - and taking away a major structural advantage they had is almost certainly going to have a detrimental effect.