I fail to understand your point.
Is it that they don't have principles therefore we shouldn't either?
This issue is not about them it's about us. Those who balk at doing the right thing because "they" are hypocrites and "they" do it too are missing the point.
In my view we have the chance to capture the moral high ground and hold it. We need to keep our own house in order and if we do so they will be forced to begin to worry about the moral pigsty they occupy.
Too many times we have been done in by our own dirty laundry. You cannot speak with any authority if you are not "clean" yourself.
Look at the spineless Republicans who laid low on the Clinton impeachment because they didn't want the finger pointed at them.