Final answer:
Paternalists argue that the best reason to oppose the legalization of drugs is to protect vulnerable individuals from the negative consequences of drug use.
Step-by-step explanation:
Paternalists argue that the best reason to oppose the legalization of drugs is that some people will be worse off if drugs are legalized. The people referred to here would be individuals who are vulnerable to the negative consequences of drug use, such as addiction, health problems, and social harms. Paternalists believe that by keeping drugs illegal, society is protecting these individuals from harm and promoting their well-being.