Sure thing Michael's initial public office “a shoo-in for Congress” thanks to the Corleone magic

Everybody undoubtedly knew who Michael was - “top Mob Boss'” son - and Michael's opponents are not going to sit back and let him have an easy, uneventful run of Congress-Senate-Presidency! without running an ignominious [successful] campaign to disgrace him

All the murderous, sordid history of Michael's family notoriety is out there for his opponents to shame him and to dishonour him
Easy pickings! indeed