It certainly looks as though Kerry never was in Cambodia; even his camp now seems to be saying that he was only "near" the country. So, would it not be considered perjury to go on to the floor of the Senate and enter into the records statements which you knew were false, just as it would if you made those statements under oath in court? On the other hand, if he really didn't know that he wasn't in Cambodia (yeah, right), does he have any regrets, shame even, and maybe even some feelings of embarrassment, about creating such a tempest in a teacup, maligning a US president, discrediting our war efforts, and giving encouragement to those who were always ready to believe the worst about our eforts in southeast asia?.......
Senators and Members of Congress are not under oath when they speak on the floor. If you testify before them, you are under oath, but they can lie all they want. They can preface their questions to you with lies that make you look bad, but if you make the slightest misstatement, you can be held accountable. They can demand that you answer, under oath, a question that bears directly on pending litigation (e.g. is tobacco addictive?), and you must answer truthfully.