OC, if I understand the question correctly, you are speaking of the President appointing his cabinet. If this is the case, it is the same as a mayor appointing the police chief and department heads.
If cabinet positions had to be elected, we'd have a greater case of gridlock than we currently do. Just look at any village or town council. Everyone would be acting on their own political agenda, rather than the unified agenda (for right or wrong) of the Pres.
If I miss understood the question, then ... Never Mind.