If there were indeed actions by a foreign power to subvert our democratic processes, then that's sufficient justification for retaliation.  Perhaps even military retaliation.  Doesn't matter if it benefitted Clinton, Trump, Sanders, or Mickey Mouse.  It can't be tolerated.  Perhaps it benefitted Trump this year, but in 2020 it could be China helping Trump's opponent.  The listen to the wailing and whining from the Trumpettes - they'll be demanding nuclear retaliation.