It became a national security issue when the Republican candidate called on a foreign power to influence the election.

If the end result is exposing criminal behavior, it doesn't actually matter who does the exposing. I mean, that's why we have whistleblower laws - because we supposedly care about exposing corruption more than leaking secrets. If they don't find anything, then they're not influencing the election. If they do find something, then it's Clinton who should be held accountable for her criminal actions, not the person/people who expose those actions.