And saying: Do penance: for the kingdom of heaven is at hand. For this is he that was spoken of by Isaias the prophet, saying: A voice of one crying in the desert, Prepare ye the way of the Lord, make straight his paths. (Matthew 3:2-3)
The beginning of the gospel of Jesus Christ, the Son of God. As it is written in Isaias the prophet: Behold I send my angel before thy face, who shall prepare the way before thee. A voice of one crying in the desert: Prepare ye the way of the Lord, make straight his paths. John was in the desert baptizing, and preaching the baptism of penance, unto remission of sins. (Mark 1:1-4)
As it was written in the book of the sayings of Isaias the prophet: A voice of one crying in the wilderness: Prepare ye the way of the Lord, make straight his paths. Every valley shall be filled; and every mountain and hill shall be brought low; and the crooked shall be made straight; and the rough ways plain; (Luke 3:4-5)
They said therefore unto him: Who art thou, that we may give an answer to them that sent us? What sayest thou of thyself? He said: I am the voice of one crying out in the wilderness, make straight the way of the Lord, as said the prophet Isaias. And they that were sent, were of the Pharisees. (John 1:22-24)
You know that the only-begotten Son is called the Word of the Father. Now we know, in the case of our own utterance, the voice first sounds, and then the word is heard. Thus John declares himself to be the voice, i.e. because he precedes the Word, and, through his ministry, the Word of the Father is heard by man.
(Catena Aurea on John 1)
With the topics of the impending election nagging every waking moment, we have the Voice to keep us focused. For instance, John stood up for marriage against Herod, and called him on other wrongs he was doing. John was imprisoned, and then eventually beheaded for it:
But Herod the tetrarch, when he was reproved by him for Herodias, his brother's wife, and for all the evils which Herod had done; He added this also above all, and shut up John in prison. (Luke 3:19-20)
"The wilderness" also brings to mind Christ in the desert. The example He sets for us:
And Jesus being full of the Holy Ghost, returned from the Jordan, and was led by the Spirit into the desert, For the space of forty days; and was tempted by the devil. And he ate nothing in those days; and when they were ended, he was hungry. (Luke 4)