Here's why attacking John Kerry by recalcitrant idiots was wrong

Kerry was and still is a good man, who was bothered by the asymmetrical damage inflicted by the United States on Vietnamese land and the Vietnamese people who didn't pose an existential threat to the American people. His anti-war activism was aimed at a cessation of such damage, not by an ideological fondness of communism. Therefore, to think "he was and still is the enemy of the South Vietnamese people" is wrong and absurd and extreme.

Proper/true thinking is hard work. One must be aware of the emotional pitfalls involved in the process of thinking. Just because the VC leaders are bad and because we really hate them, that does not mean that in order to get rid of them, any measure would do, including bombing Vietnam back to Stone Age or stopping all aid to the Vietnamese populace who have nothing to do with the VC leaders and who just happen to be their victims or sarcastically and rhetorically asking any Viet expatriate who does not agree with our extreme "thinking" to go back and live "with" the VC and VCP (Vietnamese Communist Party). Such thinking is roundly ridiculed in the common folks' sayings:

"To cut off one's nose to spite one's face".
"To throw the baby out along with the (used) bathwater".

Extreme thinking backed by persistent noisiness does not mean it has merits.

Any Vietnamese neophyte in politics, unless he's a recalcitrant idiot, would be wise to find ways to work with a former peace activist now turned Secretary of State of a superpower on this planet in the hopes of preventing China from taking over Vietnam outright, instead of demonizing him and calling him with very impolite names.