Several!!
First of all, I always believed the USA was what Revelation 13 meant. I did think the 2 horns represented both the USA and UK since the USA was an extension of the UK and remained allies all of this time. I even considered the USA being Babylon due to so many descriptions of wealth, ships in the harbor, etc etc etc.
But the real reason I always believed this, was due to the USA's founding fathers. Contrary to belief, most of the founding fathers were atheists, deists, non believers associated with the Free Mason's. Even George Washington ended his letters to the "Grand Architect of the Universe or Supreme Architect of the Universe."
If you do research and read the letters between John Adams and Thomas Jefferson, you will see how they all were atheists and Washington was a deist.
Washington's own pastor said George attended service every Sunday, but when it came time for Communion to remember Jesus, Washington would get up and leave and never once participated. His pastor believed Washington saw himself as equal to Christ, which makes him a deist.
Ironically, during this era (called the Enlightenment), these founding fathers are revealed as also being followers of Voltaire. Voltaire led a movement to discredit the idea of God and many socialists like our founding fathers, accepted Voltaire's reasoning.
Another piece of evidence anyone can read, comes from the biggest traitor to his own nation, a man named Thomas Paine. He wrote a book immediately after America gained her independence from defeating England, called "The Age of Reason." Within this book, it explains how the founding fathers tricked the Colony's churches and members to going to war with England over religious freedoms. But in reality, it was to separate the church from the state to create a Democracy. He explained how none of them believed in God, and they now have a nation based upon idealism and reasoning, not based upon religion and God.
To further that evidence (the claim by Paine in his book), let's take a closer look at the "Treaty of Tripoli." The most famous claim is made within it. It states, "The government of the United States of America is not in any sense [[founded on the Christian religion]].' And to make it even more significant, 'The government of the United States of America is not in any sense founded on the Christian religion.' That was ratified by the United States Senate without debate unanimously in 1797.
So the USA was not ever founded on the principles of God after all, they were founded on the principles of the Reasoning by those claiming to be Enlightened.
When you understand who the founding fathers actually were, it is no surprise to believe the USA will lead us into Tribulation, by the influence of Satan. After all, in today's day and age, Silicon Valley is working relentlessly on the new Quantum computer. It will be the most powerful system that will be able to control world wide banking, world wide medical, the world wide government.
And we are literally just days away from that being an actual reality..