Some may believe another Democrat President anti-Christ will be elected. One that supports making sin official U.S. law more fully than it already is (there are a few modest policies that qualify). There are already lots on anti-Christians in the world. Some Christians have an eschatological belief known as pre-tribulationism that believe there are special end times leading to Armageddon ahead with a special political leader of wickedness working for the Devil. Pre-tribbers are wrong i.m.o.
There are three Christian eschatological viewpoints that have existed since the second century a.d. The other two don’t have a future Armageddon in them. Post-tribulationsists believe the New Testament end of days occurred in the First century A.D. when Jerusalem was destroyed as the Lord prophesied it would be. He said that all the events he spoke of would occur while some of his generation were yet living and they did. Pre-tribbers ignore that and interpret the Revelation incorrectly as did Mohammad. Martin Luther said that the Book of Revelation had a lot of straw in it, and he was talking about brick making I believe. The Revelation written by John had veiled language so the anti-Christ (Caesar Nero- number 666 in Jewish number of the era) and contemporary persecutors would not have an easy time of understanding it.
The Kingdom of God is within you. Until the age of the Gentiles is fulfilled the Kingdom of God will increase. The thousand years or millennium in which that happens indicated ‘a very long period of time’- not exactly a literal expression. Actually it could go on for tens of thousands of years, I would think. What may wrap it up is the time when humanity just can’t go farther with its own devices and degrades human life with some sorts of technical morphing into horror. Then God may once more save humanity from itself, or at least the elect.