The article points out, “To be fair to Goldwater...”.
Would the successful election of Goldwater have altered the Vietnam War sufficiently to have reduced the drug culture and improved America’s worldview?
Don’t think so. The drug culture happened outside of Vietnam and in many countries that weren’t involved in it. Goldwater’s election might have slowed the progress in the US, but even bailing out of the Vietnam War early wouldn’t have stopped it.