Tupac was an activist in feminism and classism.
1. Keep Ya Head Up - a song about the rough life the average young black woman/girl goes through in terms of her place in relation not to just society in general, but also how they are treated by other black men who can make black women feel very bad and uncomfortable.
2. Dear Mama - a song in praise of his mother who raised him and his brother alone; even though he and his brother hung out with the gangs, got into trouble, and she had made a lot of mistakes in her life previously which got her a crack addiction. She stuck through to the end for him.
3. Brenda's Got a Baby - his 91 breakout single where he describes a 12 year old girl who through abuse from her family, got pregnant, went out on her own to try and support her child, was robbed, turned to prostitution, and was eventually murdered.
4. Changes - A song about poverty and the necessity to bend the law to get through life. Not an advocate for crime whatsoever, but an explanation:
Thug: "I made a G today"
Tupac "But you made it in the sleazy way"
Thug: "I gotta get pay"
Tupac: "That's the way it is"
5. Ghetto Gospel - Another song about poverty and the need to make some changes in society. "It ain't about black or white because we're human"