Double jeopardy is a pretty fundamental element to the US criminal justice system, but does it apply to a US President (or other impeachable official) and the trial-like impeachment proceedings in Congress?
For example, if a US president faces impeachment hearings for some offense, but fails to be impeached by the House, could he or she face a new impeachment hearing on the same charges if, say, a mid-term election changes the majority party?
(Let's assume, for the sake of this question, that no new substantial evidence regarding those charges is discovered, just a change in congressional makeup.)
Along similar lines, what if he or she was impeached by the house, but failed to be removed/"convicted" by the Senate? Would a fresh impeachment by the House (on the same charges) be necessary? Or could a new Senate re-convene to hold new hearings on the prior impeachment, and simply re-cast their removal vote?