Clinton had promised his release. A fair amount of elected officials have stated they believe Pollard has now served the proper term had he been sentenced properly.
What is believed to be wrong with his sentencing?
Had he been sentenced properly he’d be dead now. He sold military secrets to foreign powers. He didn’t give them to people who were better Americans out of some misguided sense of altruism and a desire to save the world from evil American troops. He’s a greedy traitor who got off easy and is now whining about his rough life.
I rarely seek information from Wikipedia, but its article on Pollard seems fairly straightforward. It states that Pollard did not honor the terms of his plea agreement. Instead, he participated in interviews with Wolf Blitzer and others in which he discussed matters the plea agreement prohibited, all prior to his sentencing.
The article further states that the judge, having obtained the SecDef damage assessment, and not bound by the plea agreement, sentenced him to life.
Nonetheless, he will be paroled in November 2015.
The article does state that Clinton had worked out an agreement for Pollard’s release, but that deal fell apart when the then-CIA director threatened to resign. Clearly, the CIA director, the SecDef and the sentencing judge know more about what Pollard did than has been made public, nor available to most elected officials.