Heal the World, We are the World, and Earth Song are all considered to be political since they are an attempt to fix some of the problems our world.
We are the World raised over $63 million for famine relief.
From Wikipedia:
"We Are the World" is a 1985 song written by Michael Jackson and Lionel Richie, produced and conducted by Bruce Springsteen and Quincy Jones and recorded by a supergroup of 45 popular musicians billed as USA for Africa (United Support of Artists for Africa).<1> The charity single was intended to raise funds to help famine-relief efforts in Ethiopia, which had experienced unusual drought and political instability in 1984/1985.
http://en.wikipedia.org/wiki/We_are_the_worldAfter the "Heal the World" song/video Michael started the Heal the World Foundation, a charitable organization which was designed to improve the lives of children. The organization was also meant to teach children how to help others.
http://en.wikipedia.org/wiki/Heal_The_WorldThe Heal the World Foundation is a charitable organization founded by entertainer Michael Jackson in 1992. The foundation's creation was inspired by his charitable single of the same name. Through his foundation, Jackson airlifted 46 tons of supplies to Sarajevo, instituted drug and alcohol abuse education and donated millions of dollars to less fortunate children, including the full payment of a Hungarian child's liver transplant.
http://en.wikipedia.org/wiki/Heal_the_World_Foundation"Earth Song" was Jackson's first song that overtly dealt with the environment and animal welfare.
http://en.wikipedia.org/wiki/Earth_Song