Character Assassination Meaning

Example : 2011 December 14, Angelique Chrisafis, “Rachida Dati accuses French PM of sexism and elitism”[1], Guardian:  For months, Dati warned she would refuse to stand aside. Now she has stunned the political class with an open letter to Fillon in Le Monde, a scathing character assassination accusing him of the "lone ambition" of a disillusioned political elite, of doing politics in a way that "never favoured women" and stopping ethnic-minority candidates from progressing at elections. She said he was committing "a sad mistake" in trying to run in Paris.