"Open your mouth for the mute, for the rights of all who are destitute."
I would quickly concede that this verse has a wide application, referring to all who are powerless, such as women (in many countries), the poor, the disabled. There are many segments of our society who are crushed under the heels of the powerful and connected. But there is one in particular on my mind...
The unborn are not only relatively powerless, but rather are utterly unable to speak up on their own behalf. Their slaughter continues every day, with no unborn voice raised in protest. Only we with a voice can claim justice for them, whether in political action, through programs such as crisis pregnancy centers, or even by the adoption of surviving babies.
That last thought leads to another principle in Proverbs 12:7: "The wicked are overthrown and are no more, but the house of the righteous will stand." As unbelievers either abort themselves into extinction, or even turn their children over to believing families, they will gradually disappear from the earth, while the godly increase and replace them.