If I'm not mistaken political officials do not have to have clearances. Look at the Clinton mob, many never had clearances. It's kind of scarey actually.
The bottom line is that he was pardoned (by Carter) and eventually given an honorable discharge. Thus there are no legal repurcussions. This is just information that should be available to the voter prior to making a decision. However, if you read the article, an inference is not proof, and they have presented no concrete proof or corroborating witnesses.
There is no way this gets out in the media without absolute proof. Perhaps Lipscomb has gotten the then Secretary of Navy to come forward, and will be publishing a story tomorrow. If not, this is going nowhere.