Legislators must reflect our values.  See Foundational American Values

An important sign of an effective leader is taking personal responsibility.  It shows a core confidence that they can handle the reality of making a mistake and are able to be honest with themselves and therefore with you. 

What qualifications are needed for those that create the laws that control our lives?

They (supposedly) represent the interest of their constituency.  Is that enough?

They make laws. 
Should they be professionals in the field of law?   Lawyers, who present the law before a judge either in the role of prosecutor or defender? 
Judges who evaluate if  laws are appropriate and how they apply?
Police who enforce the law?

How about moral law?
What about Orthodox Rabbis?  They are experts in Talmudic Law and often fill the role of judges.
How about Priests and Imams?

And how about Tax law? 
Should they be accountants?

Laws create systems of processes.
Should they be business and software analysts?

Laws have major impact on our economy. 
Should they be economists?

How about all the other fields that the laws affect.  Agriculture, Medicine, Insurance, Military etc.

To create safe efficacious medicine Drug companies employ teams of specialists with hundreds of years of  cumulative experience in biology, genetics, chemistry and other fields related to our bodies.   They conduct hundreds of tests via simulation on a computer, animal testing and clinical trials on humans.  We have a process through the FDA that evaluates and certifies medications before they are allowed to be disseminated.  We have Doctors who evaluate our specific needs and prescribe the correct medications.  Doctors are certified and operate under the Hippocratic oath of “First do no Harm”.  

What code of ethics does Congress operate under?  What certification do they have? 

The one profession Legislators really should be proficient in is Quality Assurance. 

Thought experiments, public opinion polls, photo-ops and endless rhetoric are no substitutes for simulation and field trials.  It is also essential to get feedback after the law is propagated.