Dueling Opinions?

I decided to publish a discussion I'm having over e-mail with a contributor to National Review. We'll call him AJ, which is the name of a Brazilian composer and definitely a pseudonym.

It began when AJ sent this e-mail to a list to which we belong, in response to a message from a certain individual called JDZ, who repeated the anti-Kerry smear that I tried to debunk here:

For what it's worth, I am not particularly interested in what Kerry did or did not do 30-some years ago during the Vietnam war. I am much more interested in his record as a Senator and his likely actions as President (of which, I believe his Senate record is more probative). Interestingly enough, Sen. Kerry and his supporters (like [JDZ]) seem much more interested in discussing the Vietnam era than the Senate record, presumably because they feel the former is more conducive to their campaign than the latter. Indeed, I believe that if this campaign is fought on the terrain of Kerry's Vietnam service and aftermath, Sen. Kerry will win. The best means to discredit Kerry is his Senate record -- the most liberal of any Senator according to the National Journal.

With all that said, I am nonetheless curious why Senator Kerry does not release all of his service records? It's seems there is no more basis to withhold these records than there is to withhold Theresa's tax returns.