What is the ruling on drawing caricatures of people for the purpose of expressing issues in a striking way and for legitimate goals?

It is not permissible to draw or photograph living beings, whether they cast a shadow, like statues, or do not cast a shadow. This is based on what was narrated in the Two Sahihs (Bukhari and Muslim) regarding the Prophet's (peace be upon him) command to Aisha to cut up the cloth that contained images.