ALBANY — The head investigator for the state Board of Elections probed the 2014 fundraising efforts by Mayor de Blasio and his team on behalf of the Senate Democrats and found enough “willful and flagrant” violations to warrant a criminal referral to the Manhattan DA’s office. The Daily News obtained a bombshell memo state Board of Elections Chief Enforcement Officer Risa Sugarman sent to the board’s four commissioners on Jan. 4 recommending the referral. “I have determined that reasonable cause exists to believe a violation warranting criminal prosecution has taken place,” Sugarman wrote. “The violations discovered by this investigation can...