Donald Trump is president of the USA but to many of his fans he is the God Emperor. Not everyone is aware what that means. In fact not everyone who uses it to trigger the left knows what it means. So as a fan of Warhammer 40k let me enlighten you.
Warhammer 40k is a sifi universe described in dozens novels and a tabletop game. Videgames in warhammer 40k style also exist but those need some work.
What matters is that the most important person in that universe is the God Emperor of Mankind and I'll explain who he is. Some things from this point on will be written as if 40k is real and the current year is 40000 (40k).
First thing you need to know is that in 40k you travel through space by flying your spaceship through hell. Actually it's called the Warp and it's also the place where souls come from and specials souls give you magic powers. But I'll spare you the details.
All races (meaning both humans and various aliens) have some connection to the warp however small. Unfortunately there are daemons in the Warp. The worst of those Daemons are called Chaos Gods.
In the year 8000 before Christ the Shamans of earth (humans with magic) became aware that these daemons were eating the souls of Shamans when they tried pass through the Warp to reincarnate. This meant that humanity would lose it's wisest and most powerful members. The Shamas foresaw that we would need them to fight of the daemons and the various kinds of awful aliens waited for us in space. So they came up with a bold plan. They committed mass suicide so the could overwhelm the daemons. And it worked. They tore through the Warp like a cleansing flame.
But the second part of the plan was truly daring. They all reincarnated into the same body. One child was born with all the power and wisdom of all of earths Shamans combined. This kid was so overpowered he rewrote his own DNA to make himself biologically perfect . It is not known what his parents called the boy, but many of the most powerful and benevolent figures from myth, history and religion were him in disguise. (remember this)
As he lived for millennia after millennia he constantly tried new ways to protect humanity from chaos and bring order to universe. Eventually with his help humanity build an wonderful advanced Star Trek like utopia. But it all fell apart. In the year 30000 humanity was scattered across space in our many colonies. Much knowledge was lost in the war with our own robots and the birth of a new Chaos God caused a huge natural disaster across the universe.
It was a time of despair. Humanity was preyed upon by aliens looking for slaves, food and sadistic fun. Poverty and starvation were common and billions prayed each night for a savior.
Against all odds they got one. On holy Terra (earth) a new warlord started conquering lands. But he was different from the other scum. He was kind and just. He was noble and brave. Life was good under his rule.
Slowly insane rumors started spreading about him. They said his touch healed the sick and even fixed machines. They said he killed thousands of enemies without even breaking a sweat. They said warriors who joined him were transformed into super soldiers. His people began to wonder if he was a God?
When the warlord revealed his true self history changed forever. That kid I told you about stood before them in perfect immoral health, built like a Greek God twice as tall as a tall man. He was handsome beyond anything art had ever approached and as his hair waived in the wind a halo of righteousness glowed around his head. He had the power and wisdom of the shamans and 38000 years of life experience.
He was exponentially superior in every way to all other men. The sight of him made men fall to their knees crying tears of joy as they swore oaths of eternal loyalty. Women cried out in orgasm after orgasm after a mere glimpse of him.
Boldly he proclaimed that to save humanity he would have to rule it. And so he declared himself Emperor. Together with his ever growing armies of adoring subjects he conquered almost all of the universe making it the Imperium of man. Despite his insistence that he was not a God, he failed to stop people from worshiping him. The combined faith of hundreds of thousands of billions even turned him into a real God over time.
Believe it or not that was a very short version of this story and there are lots of things I didn't get to.
I guess I really need to mention that the God Emperor does a lot of very immoral things (like genocide of aliens because they might be a threat to the survival of humanity or slaughtering his own soldiers because they had to be replaced by a new model and of course being an authoritarian dictator) but he never does these things for personal gain. In 40k the scariest most awful sifi universe ever the only hope lies in 3 simple words.
"The Emperor protects"
That's why we call Trump the God Emperor. We are jokingly implying that he is just a disguise for the Emperor and that this is one of these 'powerful and benevolent figures from myth, history and religion'.
This is a joke but it hides a deeper truth. The man is flawed and he'll occasionally betray us a bit like with that gun control bullshit. But in an age of madness and horror we need him and the power of our faith in him to keep Chaos at bay.
This faith gives us the strength to keep going. It makes us want to be more than we are and fight battles that should not be winnable.
For the Emperor!