The herd is wise, but why doesn't it get a move on?

"However inconsistent politicians can be, that is not a quality of the electorate: when it makes a negative judgment of any political leader, it rarely changes its mind." Tom Harris today in the Daily Telegraph. Are there exceptions to to his rule? 

His aphorism reminds me of Edmund Burke's: "The individual is foolish; the multitude, for the moment is foolish, when they act without deliberation; but the species is wise, and, when time is given to it, as a species it always acts right." 

Or to quote Boris in his last speech to the House as Prime Minister “As we've seen at Westminster, the herd instinct is powerful. When the herd moves, it moves.” 

I hope it moves fast against Liz Truss.