SAN DIEGO – Hundreds of protesters who had gathered in Chicano Park Friday morning began marching toward downtown around noon to demonstrate against proposed changes to federal immigration policies. Police estimated the crowd at around 1,500 protesters, including students and others. The group began marching through city streets during the lunch hour. About 1,100 students didn't show up for classes at San Diego city schools Friday, a school district spokesman said. Students around the county – and in other locations – have staged protests all week. “We have been bracing for a big day,” said city schools spokesman Steven Baratte....