Is Satan's kingdom here on earth? Reading Matthew 12:26

If Satan drives out Satan, he is divided against himself. How then can his kingdom stand?

I cant seem to pin point where is his kingdom? Evil men dont seem to be united?
Let's take a long look at the Scriptures around your referenced Scripture:
Matthew 12:25 through 28 KJV

25  And Jesus knew their thoughts, and said unto them, Every kingdom divided against itself is brought to desolation; and every city or house divided against itself shall not stand:
26  And if Satan cast out Satan, he is divided against himself; how shall then his kingdom stand?
27  And if I by Beelzebub cast out devils, by whom do your children cast them out? therefore they shall be your judges.
28  But if I cast out devils by the Spirit of God, then the kingdom of God is come unto you.

and see if Jesus was actually saying that Satan had a Kingdom to begin with. What Jesus was retorting to was the verse preceding this retort (Matthew 12:24):
But when the Pharisees heard it, they said, This fellow doth not cast out devils, but by Beelzebub the prince of the devils.
Jesus was incensed by their claim that he was getting his power to do these miracles from Satan, and his angry retort was meant to marginalize them.
In verses 26 and 27 He is belittling them by:

saying that If Satan is ruining his own plans, If He had a Kingdom by fighting against himself he would be destroying his own Kingdom.

Jesus is saying and if as you say I am getting my power from Satan, where are your people getting their power from?


The last stone he casts is in verse 28 where he tells them knowing what I have just told you my power must come from another source. and if my source is God then you have just seen the Kingdom of God.
Here are some other Scriptures concerning Satan's supposed power which you may find will help you in understanding Satan. Please remember that Jesus himself said that Satan was a liar and the father of lies.
Matthew 4:1-11  KJV

Again, the devil taketh him up into an exceeding high mountain, and sheweth him all the kingdoms of the world, and the glory of them; And saith unto him, All these things will I give thee, if thou wilt fall down and worship me.

Mark 3:22-26  KJV

And the scribes which came down from Jerusalem said, He hath Beelzebub, and by the prince of the devils casteth he out devils. And he called them [unto him], and said unto them in parables, How can Satan cast out Satan? And if a kingdom be divided against itself, that kingdom cannot stand. And if a house be divided against itself, that house cannot stand. And if Satan rise up against himself, and be divided, he cannot stand, but hath an end.

In This Scripture what Jesus is pointing to is that if what they were claiming were true then Satan does not have the power of God since he could not do what they claimed and be eternal.
Revelation 2:13  KJV

I know thy works, and where thou dwellest, [even] where Satan's seat [is]: and thou holdest fast my name, and hast not denied my faith, even in those days wherein Antipas [was] my faithful martyr, who was slain among you, where Satan dwelleth.

Revelation 12:9-12  KJV

Therefore rejoice, [ye] heavens, and ye that dwell in them. Woe to the inhabiters of the earth and of the sea! for the devil is come down unto you, having great wrath, because he knoweth that he hath but a short time.

Revelation 3:9  KJV

Behold, I will make them of the synagogue of Satan, which say they are Jews, and are not, but do lie; behold, I will make them to come and worship before thy feet, and to know that I have loved thee.

Revelation 12:9-12  KJV

Therefore rejoice, [ye] heavens, and ye that dwell in them. Woe to the inhabiters of the earth and of the sea! for the devil is come down unto you, having great wrath, because he knoweth that he hath but a short time.