Kennedy must have been miffed that he couldn't beat Carter in the Democrat primaries.
Speaking of Jimmy Carter...if the media couldn't muster the outrage over a former president making back-door deals with the Soviets via their ambassador to electorally defeat Reagan and stifle his foreign policy (both in 1980 as president and 1984 as citizen), than I can't imagine Kennedy will make much of a splash.
After all, this was at same time Democrats like Jim Wright were writing letters (Dear Commandante) in support of the communist Ortega in Nicaragua, attempting to undermind Reagan's Latin America policies. Or Leahy, leaking secret details on Iran/Contra and endangering our overseas assets...actually resulting in the death of an informant.
The Democrats are the Party of traitors and treason...and they always have been.