Almost every night, all of America is witness to Joe Biden's seemingly progressive mental decline on full display. The decline expresses itself in surprisingly different forms each night. It all adds up to what we laymen are certain is age-advanced dementia. Biden can't remember words, places, or people. He recalls he was once in the "Obiden-Bama" administration and is now running for "U.S. Senate." Facts and figures are even more challenging. Even hardcore conservatives cringe with sadness as Biden slurs his way through the mental fog. So why is Joe Biden running for president, given his age and mental decline?...