Former President Donald Trump’s hush money trial, scheduled to begin later this month, is so critical because it was in many ways the precursor to his scheme to overturn the 2020 presidential election, legal expert Norm Eisen told CNN’s Sara Sidner on Tuesday. Manhattan District Attorney Alvin Bragg is prosecuting the case as felony business fraud that was undertaken in service of covering up an illegal campaign finance scheme to conceal Trump’s affair with adult film star Stormy Daniels from the voting public ahead of 2016 — and prosecutors are reportedly planning to bring in tons of witnesse…