I think “impactful” acknowledges that the person has used kinetic energy to effect change. Examples would be burning another person with a cigarette, sodomizing him with an iron rod, and murdering him.
Guess I”m just old-fashioned. To me, it’s still “had an impact on”, etc.
But there are far more important things than semantics this election season, that’s for sure. Our Pres. MUST win, so he can “have an impact” on America’s future. :-)