evidence: Sanders is not the first would-be president to confront scrutiny over long-ago travels. When he ran in 1992, Bill Clinton faced questions over a 1969 trip to the Soviet Union. John F. Kerry, the Democrats’ 2004 nominee, took heat from Republicans for a 1985 visit to Nicaragua — the same year that Sanders visited. [...] Sanders’s visit to the Soviet Union in the late spring of 1988 offered a more complex picture. The CCTV video marking the trip — which was posted online just last year — begins in an unlikely place: Sanders’s sun-splashed wedding on the shores of Lake Champlain. The next day, the newlyweds were off on what Sanders has described as "a very strange honeymoon." [...] William Taubman, an Amherst College historian of the Soviet Union who was living there at the time, said Sanders’s comments need to be understood in the context of the moment, which was dominated by then-leader Mikhail Gorbachev’s policy of opening and liberalizing his nation. Sanders appeared to have found cause for optimism in such a transformation, while also casting a critical eye on the Soviet past -- and on the status quo that Gorbachev was attempting to change.