To do so, he should begin with a question. Why have former U.S. Deputy Defense Secretary Lawrence Korb, former U.S. Senate Intelligence Committee Chairman Dennis DeConcini, Ronald Reagan's National Security Advisor Robert McFarlane, former CIA Director James Woolsey, former Attorney General Michael Mukasey, former Deputy Attorney-General Philip Heymann, former Secretaries of State Henry Kissinger and George Schultz, 39 U.S. Congressmen, 18 U.S. ex-Senators and even the European Parliament (on September 16th, 1993) repeatedly called for Pollard's sentence to be commuted.
This answer, quite simply, is because Pollard's punishment did not fit his crime.
McFarlane went so far as to write that Pollard's imprisonment was "disgraceful and mean-spirited," and "well beyond what any court would sentence for the same action today." He called Pollard's life sentence a "great injustice" and disproportionate to the crime he committed.
In 1987, Pollard pleaded guilty in a plea agreement (a deal quashed by the judge at the request of Caspar Weinberger, then-Secretary of State who had a visceral dislike of Israel) to one count of providing classified American intelligence information to an ally - Israel.
However, a newly-declassified 1987 CIA Damage Assessment indicates that the information Pollard provided to Israeli intelligence related to Tunisian, Syrian, Pakistani, Iraqi, Libyan, Iranian and Soviet nuclear, chemical, and biological warfare capabilities - vital intelligence that Israel was legally entitled to receive in accordance with an Executive Order signed by President Reagan, but which was being withheld as retaliation for Israel's pre-emptive strike on Iraq's nuclear reactors.
It included photos of the PLO headquarters in Tunisia and information on Soviet arms shipments to Syria and other Arab states; Tunisian and Libyan air defense systems, information on Egyptian missile systems and information on planned terrorist attacks against Israeli civilian targets. With regard to Syria, in particular, Pollard provided documents concerning a suspected research and development facility, the Syrian electronics intelligence (ELINT) system, remotely piloted vehicles, a national command, control, and communications center in Damascus, Syrian military units to which Soviet advisors were assigned, and medical intelligence information on then Syrian president Hafez al-Assad.
The common denominator in these documents was that they all related to the existential threat posed to Israel by these hostile Middle Eastern Arab/Persian/Asian countries.
Pollard was never charged with treason, was not motivated by profit, and was never indicted for harming the United States or for compromising U.S. capabilities, codes, agents, or war plans. He was indicted and convicted on only one charge - one count of passing classified information to an ally - without intent to harm the United States.