according to this, the groups that protested were not just the air force association and american legion (which both lobby on behalf of veterans), but also individual WWII veterans from around the country.

as the grandchild of a (now deceased) nagasaki survivor, i have heard this rhetoric from not just veterans, but their children and grandchildren as well. in my experience interacting with them (irl, not online), i have never heard a single one criticize the atomic bombs, ever. that’s just my experience, though.