new play considers the morality of punishing political crimes more severely

Although it arguably violates the First Amendment, judges still consider defendants’ political beliefs and public statements when deciding on sentences. This occurred, for example, in the cases of Lynne Stewart and Tim DeChristopher. Today’s New York Times includes an article by playwright David Mamet on his new play related to the morality of punishing political crimes more severely than other offenses:

In “The Anarchist” a woman has been convicted of murder, for participation in a bank robbery by a self-proclaimed political organization. She has served 35 years, a big portion of her life sentence, and pleads to be released; if the crime were mere robbery-murder and not deemed political, she would, by custom, have been paroled, with good behavior. Her argument has merit.

The rationale for continued incarceration under these circumstances is that in light of the prisoner’s beliefs, she poses more of a threat than someone convicted of a murder unrelated to ideology. But is this true? And even if so, isn’t it inconsistent – as Mamet points out – for a court to disregard political motives when it comes to mitigating factors but give them weight when it comes to aggravating ones?