What must obtain energy through their diets

Heterotrophs

Explanation:

The organisms that can not make their own organic food obtain the energy and nutrition from the food they eat. These organisms that depend on plants or other organisms for their energy are called heterotrophs.  

For example, the human can not carry out photosynthesis as plants do. So, human obtain their energy from the food derived from plant and/or animal sources they eat.  

the framers of the constitution insisted that federal judges be nominated instead of elected due to their desire to have judges above the shifting whims of the masses.

the hope, whether achieved or not, was that federal judges would only be beholden to the law and that by not having judges be elected, they would be protected if that law dictated an outcome that ran counter to popular opinion.