"YOU are making excuses for Clinton, not me. I just want to know why there are two sets of laws, one that apply to those you dislike, and one that applies to those you approve of?"
Notice that you are asking that convicted perjurers be punished.
Libby was convicted. Clinton was not. That's what impeachment and conviction are all about. The House impeaches (indicts, effectively) and the Senate tries (and convicts or not). Clinton can't serve time for something he was not convicted of. Libby can serve time because he was convicted.
Does that make Clinton a saint? No. Does that make Libby a felon? Yes.