The ghost haunting the 2020 election

(CNN)What is haunting the campaign of 2020? The ghost of 2016, when Donald Trump overcame dismal mid-October polls and eked out a surprise Electoral College victory over Hillary Clinton to become president. Trump's supporters are hoping it will happen again, that the polls aren't registering the full degree of his support among voters. At the same time, many of Joe Biden's backers are nervously eying his lead in key swing state polls, worried it won't endure for the next nine days. But it's not 2016 anymore. So much has changed in four years: Trump is no longer the new disrupter, he's a president trailing multiple incendiary controversies as he seeks four more years. And Biden isn't Hillary...