The "crazy Western states"- Utah, Idaho, Wyoming- will probably never vote Democratic again. The GOP is entrenched there to an insane degree, partly by tradition but mostly because of the states' far-right orientation. I would be stunned if any Democrat could poll 45 percent in the next half-century.
Some huge swings:
Kansas 1928 GOP wins 58.2-40.8
Kansas 1932 Dem wins 53.5-44.1
Georgia 1972 GOP wins 75.0-24.6
Georgia 1976 Dem wins 66.7-33.0
New Hampshire 1984 GOP wins 68.7-31.0
New Hampshire 1988 GOP wins 62.5-36.3
New Hampshire 1992 Dem wins 38.9-37.7-22.6
New Hampshire 1996 Dem wins 49.3-39.3