A Democratic congressman whose mother and stepfather died of COVID-19 during the pandemic on Wednesday slammed comments made by Republican firebrand Marjorie Taylor Greene, who insisted on calling Dr. Anthony Fauci “Mr. Fauci,” an overt attempt to discredit the nation’s former top infectious disease expert over his handling of the pandemic. At the hearing Monday, Fauci, the former head of the National Institute of Allergy and Infectious Diseases, was grilled by Republicans in a spectacle that featured prominent conspiracy theories such as claims that the true origin of the coronavirus was cove…