Which "worst impulses" are you concerned about controlling "right now"? Because the only impulse providing a check against Chinese and Russian national interests globally, is the current administration's readiness to go to war - if necessary - to preserve a semblance of rule-of-law. US soft power hegemony was spent, utterly depleted during and after Gulf War II. Rebuilding it requires a hard power economic and military commitment no other candidate/administration was willing to undertake.