Red Herring

A red herring is a smelly fish that would distract even a bloodhound. It is also a digression that leads the reasoner off the track of considering only relevant information.

Example:

Will the new tax in Senate Bill 47 unfairly hurt business? One of the provisions of the bill is that the tax is higher for large employers (fifty or more employees) as opposed to small employers (six to forty-nine employees). To decide on the fairness of the bill, we must first determine whether employees who work for large employers have better working conditions than employees who work for small employers.

Bringing up the issue of working conditions is the red herring.