Great point. The Clintons had this effect in the mid-1990’s if I remember correctly.
Look at what happened in the 1976 election. As a Washington outsider, Ronald Reagan very nearly unseated a sitting president for the nomination. A completely unknown Jimmy Carter trounced what was one of the strongest slates of candidates by any party in history (Scoop Jackson, Mo Udall, Frank Church, Birch Bayh, etc.).