Most able at what? Most people who are in elected office, or who have been in elected office, have a certain repertoire of skills in getting along with other people and in keeping track of mutual obligations that helps make the political process work. Some scientists or engineers who become politicians

http://www.whitehouse.gov/about/presidents/jimmycarter

http://mcnerney.house.gov/

http://en.wikipedia.org/wiki/Vern_Ehlers

http://holt.house.gov/

http://olver.house.gov/

http://en.wikipedia.org/wiki/Bill_Foster_(Illinois_politicia...

http://sharp.sefora.org/issues/111th-congress-degrees-by-typ...

have had some degree of those skills, and some people with other academic degrees have gained understanding of how science relates to public policy.

http://press.princeton.edu/titles/9226.html

But scientists and engineers are still fallible human beings,

http://yalepress.yale.edu/book.asp?isbn=9780300123852

and the political process will still come under influence of concentrated interest groups

http://www.econlib.org/library/Enc/PublicChoice.html

regardless of which people fill the offices.