Donald Trump is now officially President-elect Trump after Congress certified his election win with Vice President Kamala Harris overseeing the count.

Four years ago -- the U.S. Capitol saw a different scene on this day, one that Dr. Joe Morris said is one of the darkest days in American history.

But on January 20, Donald Trump will once again be President Trump, a feat that Morris said is one of the most remarkable comebacks in all of American politics.