Trump prepares scorched earth campaign against Biden

President Donald Trump makes no secret of the scorched earth campaign he'll mount against Democratic frontrunner Joe Biden -- complete with questioning the former vice president's cognitive abilities and accusing him constantly of corruption.A veteran senator and former wingman to Barack Obama, Biden has shot into pole position ahead of fiery leftist rival Bernie Sanders with a soothing message of restoring calm and "decency" to America.As part of his folksy plain "Joe" persona, Biden often says