If Darwin was into politics rather than exploring the nature of the species...
he would have discovered that a person can, at will, change their mind, or at least their representation of their stated position, with nothing more than some input and stimulus of a set of outside opinions that are counter to the person's previously stated position and 'beliefs'...
while not exactly technically adherent to the theory of the evolution of the species, and therefore not truly an 'evolution', it has become the political term 'flip-flop' to define its distance from true 'evolution'...it defines and explains the ability, especially in politics, to determine that a tide is rising against stated positions and, to curry favor with the population mass within that tide, make a sudden opposite, or reversal, in direction...
the astute politician (and their supporters) can then explain that their position has 'evolved'...it isn't that they were wrong in the first place, but once they finally realized enough people felt otherwise it became politically expedient to 'evolve'...in some instances, and usually too late, to save one's career, position, and in some instances, head...
Darwin surmised that evolution, while constantly ongoing, is fairly slow in terms of being able to chart the great changes relative to the particular specie's nature....
Apparently in politicians that time frame is, when necessary, very quick indeed...