If Trumps brings us to war with NK, how does our nation react?

[Absentee Voting Ghost of Ruin]

If President Moron is the one who really starts the war and it is percieved in the US to have gone badly, then I think he drops to about 30% approval and stays there. Really badly might drop him even below that. But if it is seen to go well, even if only in the short term, then I think he climbs into the mid-forties. Even higher if he can keep his mouth shut.

In this context good means under a thousand non-North Korean civilian casualties, no nukes going off, and the Kim regime deposed. You'll hear 'only Trump could have pulled it off' and red, white, and blue pro-intervention stuff from all the propaganada channels.

Badly would be about as expected. Tens of thousands of casualties outside North Korea, including in our military. A humanitarian crisis of huge proportions. Possibly a nuke is used in combat. World economy goes into recession. Media says things like "President Trump killed more civilians and American soldiers in a week than Bush did in a year, and we still haven't defeated North Korea

Very badly would stop short of WWIII but still be terrible. possibly multiple nukes used, including on cities. High American casualties or prominent American military failures. civilian casualties in South Korean or Japan approach a million. A North Korean government hostile to the United States remains in power, possibly due to Chinese (or Russian) threats of intervention.

Worse than that and he probably gets impeached.

[Absentee Voting Ghost of Ruin]

Would his poll numbers decline or rise? Would that be temporary?

And how would the nation react if his actions really do lead us to WWIII?

In that case, I suspect Trumpolini will end up being an extremely appropriate nickname for him.