Monuments, city streets, elementary schools and other places honoring César Chavez’s name and the legacy of his labor movement stretch across states. Now, in the wake of explosive sexual abuse allegations against the Latino icon, the name overnight has become more of a stain. Some of the institutions and local governments overseeing sites across the country bearing the Chavez name have already started the process Thursday of erasing it. Besides buildings and street signs, they also want to take steps to rename César Chavez Day, a federally proclaimed holiday that falls on his March 31 birthday.