From a legal perspective, allow me to interject.
Black's Law Dictionary (which is the premier authority of the definition of law terms in the legal circle, defines "perjury" as the following:
"the willful assertion as to a matter of fact, opinion, belief, or knowledge, made by a witness in a judicial proceeding as part of his evidence, either upon oath or in any form allowed by law to be substituted for an oath, whether such evidence is given in open court, or in an affidavit, or otherwise, such assertion being material to the issue or point of inquiry and known to such witness to be false."
Given that definition, it's quite doubtful Clinton committed perjury, and as such that is likely why he was neither charged with perjury in any criminal proceedings, nor was he convicted of the perjury charge in the impeachment proceedings.
To wit:
Clinton's denial of the Lewinsky affair did occur under oath; however, it occurred during a civil proceeding, namely the Paula Jones sexual harassment lawsuit. There was no "crime" as this was not a criminal indictment. Now, I don't know if you are aware, but it is possible for perjury to still be committed in civil proceedings, but this instance did not stand legal mustand.
Now putting aside the merits of the Jones suit (which was in fact later dismissed for failure to state a cause of action) or the questionable funding sources utilized for the prosecution of the suit, you still have to look at things objectively.
Clinton lied about what was a consentual affair with an adult who was not Paula Jones. The relevance of this to the allegations made by Jones escapes me. This was a highly irrelevant line of questioning with no bearing on the issue of the suit, which was whether then Gov. Clinton made inappropriate advances towards Ms. Jones without her consent. What President Clinton did with Monica Lewinsky, and the fact that he denied it even though it was in the end true, was not--to quote Black's--"material to the issue or point of inquiry" of the underlying lawsuit. As such, no perjury.
Let me provide you with a real world example. Say you are being sued for causing an accident which injured the plaintiff. Let's say they say you ran a stop sign. You're deposed or called to the stand to testify. You are put under oath. The attorney asks for your full name. Say your middle name is Gaylord, but for obvious reasons you don't want to disclose that fact. So you lie and give another name instead. So you've techincally lied while you are under oath. But it's ridiculous to think any prosecutor is going to bust you for perjury for lying about something that was not in any ways relevant to the issue at hand, which is whether you ran a stop sign which caused the accident. That would be a tremendous waste of time, money and the court's resources to do so. Therefore, that is why perjury only pertains to issues relevant to the case at hand.
And finally, while you may believe the Jones suit dealt with a crime, the fact is it was not a criminal proceeding. It was a civil matter. So that too is in error.