In Vietnam itself there was not a “bloodbath” in any way comparable to what occured in Cambodia. There was persecution, starvation, and repression, and a lot of guys carted away to re-education camps, just as all who opposed the North Vietnamese said would happen, but nothing comparable to what Mao, Stalin, or Pol Pot did.
Of course part of this was because the North, by its own devices and through the Vietcong, had spent twenty years attacking Vietnames civil society throughout the country, focusing on anyone who tried to become a civic leader not allied with the Communist regime.
Everything is relative. Mao and Stalin killed far more people than were killed in the Holocaust by the Nazis, but that doesn't make the Holocaust any less significant. The Black Book of Communism, published by Harvard University Press in 1999, estimates that two million Cambodians and one million Vietnamese were slaughtered by the Communists in Indochina.
An estimated 528,000 were killed by the Vietnamese Communist government after 1975. This does not include the hundreds of thousands of boat people who drowned, died of starvation or thirst, or were murdered by pirates after fleeing Vietnam in desperation in over-crowded small boats in the hope they might somehow find their way to land and a chance at human freedom. Perhaps half-a-million boat people managed to make it safely to land. Estimates of those who died range from a few hundred thousand to half of those who fled. "Anyone who still denies that a bloodbath occurred after America abandoned the peoples of Indochina is either lying or totally out-of-touch with reality. To this tragic cost must be added the suffering of the many tens of millions who were consigned to Communist tyranny by our decision to abandon them."
In his 1971 testimony before Congress, Kerry seems to have taken several positions on the issue of recriminations, arguing at one point that perhaps 2,000 or 3,000 people might face political assassination when the Communists took over, but total recriminations would be far, far less than the 200,000 a year who are murdered by the United States of America. Kerry is a fool and a traitor.