“The only way Congress can formally accuse a President is by impeachment.”
Ah.. I think I see where you are going with this. No, Nixon wasn’t impeached. He resigned before the articles of impeachment could go before the full house for a vote.
What came out of committee was a recommendation to impeach. Once Nixon resigned, the impeachment went away. But that didn’t stop the potential of a criminal investigation into Nixon’s actions for obstruction. That’s why Ford pardoned Nixon. Had nothing to do with the impeachment.
Real quick on Hillary. Since the FBI or any police organization is not looking at pressing any charges against Clinton, there is nothing to pardon her for. As far as they are concerned, she hasn’t committed any crimes to be pardoned for.