If you wish to reduce bad behavior, it has to start with you, not the person who you think is behaving badly.
Responding disrespectfully to someone who is acting poorly just leaves the world with another badly behaving person. You must set the example you want to see.
Acting badly because someone else is acting badly is not an excuse to act badly. You are responsible for your behavior no matter what other people are doing.
Strive to set an example you will be proud of no matter how you are feeling and no matter who sees it.