Dude 1: I shudder to think that there may be an alternate universe out there in which McCain-Palin won the elections! Wait, she could be PRESIDENT in this one!
Dude 2: There is such a universe. In that universe Gore and Lieberman won. Gore was killed by an Iraqi-Iranian-Pakistani Terrorist while he was looking out a window in the Twin Towers. President Lieberman made a tearful speech declaring Gore a martyr. He the declared World War on Islam and bombed Egypt.
Despite popular belief, an alternative fact is not a lie, but a fact derived in an alternate reality or parallel universe. These facts are often hard to verify as all data and analysis doesn't leave the alternate reality or universe where it was derived. Furthermore most people are not able to access the alternate reality or universe, as it requires special abilities reserved for those with a wonton disregard for logic, and zero cognitive dissonance.
Trump: Hey Pence, Nickelback is the best selling band of all time! We need to book them for the inauguration.
Pence: Save your alternate facts for the media and twitter.