No, it is not common sense. It is judgement based on an assumption. You are assuming that anyone who stole a pack of gum will turn into a bank robber because they are both thieves, and the only thing preventing that is the opportunity to rob a bank. I'm sorry, but that is an incorrect assumption and an unfair judgement.
Your issue with Cruz clearly goes well beyond his lies, as everyone on that stage has lied at some point in their lives. Does that make them all as corrupt as Hillary? No... it does not.