I will respond in fuller detail in the next few days.
For now, I'll just say
1) The foreign policy arguments Eugene McCarthy and Robert Kennedy-whose foreign policy proposals were essentially identical to McCarthy's- DID actually resonate with the voters. Those two candidates won a total of 67% of the vote in the Democratic primaries in 1968- McCarthy actually won the popular vote in the primaries over Kennedy 37% to 30%(in part, because McCarthy was in two large-state primaries before Kennedy entered the race and after he was assassinated). The polls throughout the summer of 1968-Kennedy was assassinated in June- showed that McCarthy was running a much stronger race against Richard Nixon than Hubert Humphrey ever did, and that on several occasions McCarthy was actually beating Nixon in the polls. The fact that he didn't win the Democratic presidential nomination doesn't mean his views on foreign policy and defense weren't popular- it means that the process used to nominated a Democratic presidential candidate wasn't, ironically, democratic- most of the state delegations were chosen at state conventions or by the state party leadership itself- in once state, the 1968 convention delegation was actually chosen in 1966, at a time when everyone simply assume Lyndon Johnson would be renominated by acclimation- and the party's insistence on disregarding the massive support for the two Democratic "peace candidates" of 1968 is reckoned, by many analysts, to be the main reason the party narrowly lost the presidency in November- and the only reason Hubert Humphrey, the candidate Lyndon Johnson essentially imposed on the party- was able to make it a close race- he was 13 points behind for most of the first month after the convention- was that he somewhat broke with Johnson on Vietnam in late September- a change that turned that 13 point deficit into essentially a dead heat by election day. Humphrey had wanted to reach out to the McCarthy and Kennedy supporters before and at the Chicago convention, but Johnson had refused to allow him to- and Johnson could have stripped Humphrey of the nomination at any point during the convention simply by having his own name placed in nomination, since most of the "Humphrey" delegates were simply pro-Johnson delegates with no real personal loyalty to Humphrey himself.
As to the 1972 result- the truth is that the shooting of George Wallace was always going to throw his 13%-15% of the voters(as shown in opinion polls during the spring) to Richard Nixon as a bloc; that, and the "China trip", were always going to guarantee that ANY Democrat nominated as president that year would be doomed to a landslide defeat. McGovern's campaign had flaws- and I never said the Democrats should run any campaign exactly as his was run- but it did resonate with voters on Vietnam- Nixon didn't run in 1972 as the pro-war candidate, but, instead, as the POST-war candidate- his message wasn't "a vote for me is a vote to keep the war going", but a vote to essentially let him tie up the last loose ends.
What I said Democrats should use from the McCarthy and McGovern campaigns is the willingness to admit it's time to stop trying to use every international conflict as a pretext for geopolitics and militarism. There was no excuse for the party to have a defense policy that allowed Trump to call Democrats "warmongers", and, while it is legitimate to support Ukrainian sovereignty and independence, the Democratic administration of the era should NOT have pushed to have Ukraine become a NATO member and, presumably, to have Western troops or missiles stationed on Ukrainian soil. It was entirely possible to defend Ukraine from Russian aggression without insisting on doing something NO Russian leader will ever accept- having Western troops at Russia's borders.
We should also move to a balanced approach on the Israel/Palestine issue rather than continually giving unquestioning support to everything the IDF does to ordinary Palestinians- and yes, that means telling AIPAC to piss off, since all that organization wants is permanent regional war.
