I absolutely love how Marguerite, in Chauvelin’s eyes, is a symbol of wisdom and freedom in the musical.
He wants her. He objectifies her not as a woman, but like a national treasure. He is possessive of what was once her ideals. He wants her to be like him. He wants her to become a martyr. He wants to eternalize her into a symbol of their new society.
I believe this is also what the 1982 film tried to portray (the musical is directly inspired by this film adaptation).
They got rid of Marguerite’s agency over her own sins and completely antagonized Chauvelin in order to put an emphasis on this form of objectification.
As the story nears its end, Chauvelin loses all interest in Marguerite, upholding his own ideals above his yearning for her. He was to make an example out of her. Instead of a symbol of the revolution, he would turn her into a national traitor, a symbol of evil, everything that goes against his idea of “democracy”.