Puns:Idiots Are Taking Over
MENSA is an organization for people with high IQs. Its sole requirement for entry is that potential members must score within the top 2% in any approved standardized intelligence test.
Watson, it's really elementary refers to Dr. John H. Watson from the popular Sir Arthur Conan Doyle novels about the detective Sherlock Holmes.
The Industrial Revolution was the major technological, socioeconomic and cultural change in the late 18th and early 19th century resulting from the replacement of an economy based on manual labor to one dominated by industry and machine manufacture.
Flipped a bitch means to make a U-Turn (or a 180 degree turn.)
Evolution is the process by which populations of organisms acquire and pass on novel traits from generation to generation. It was introduced by Charles Darwin (The same Darwin that's rollin' over in his coffin.)
In the lyric someone flopped a steamer in the gene pool a steamer refers to a warm, steamy poop. The Gene Pool of a species or a population is the complete set of unique alleles that would be found by inspecting the genetic material of every living member of that species or population.
Charlton Heston is an actor who starred in a film called Planet Of The Apes in which a primate (or monkey-like) species had taken over the Earth. He is also an honorary life member of the National Rifle Association (NRA), and was its president and spokesman from 1998 to 2003.
Populism is a political philosophy or rhetorical style that holds that the common person is oppressed by the elite in society, and that the instruments of the State need to be grasped from this self-serving elite and used for the benefit and advancement of the people as a whole. Those who practice this are called Populists.