They will marry, and have children of their own. Years down the road, you may notice that a descendent of Analisa has taken over leadership of the capitalists, or perhaps one of their children has become the leader of the military faction, following Frederico's military career path. Many times you will notice children following in the footsteps of their parents. This family track is not only true for career, but often for faction membership, and even overall happiness with you as El Presidente. A family that hates you early on may end up spawning your successor or a rebel or two.
Families remember how their members are treated.
Arrest a Verde, and the rest will lose respect for you. Have a Ramirez eliminated, and don't expect support from their family. Bribe a Del Rey, and not only will the recipient like you, but his extended family will lean more your way as well. I really, really like the way Tropico brings the citizens to the forefront of the game. Rather than simply being numbers and totals, your citizens are citizens.