'Dauernd seine Gesinnung ändern' gives the incorrect impression of inconsistency or opportunism, whereas tergiversation (tergum: the back, versare: to turn) denotes a one-time "desertion of a cause, position, party, or faith"; e.g. "after his visit to the USSR, Arthur Koestler tergiversated by renouncing his belief in communism".
A second meaning of the term describes 'prevarication', or what a politician does when asked a direct question.