WASHINGTON (AP) – In the first major policy proposal of her Democratic presidential campaign, California Sen. Kamala Harris is focused on boosting the salaries of teachers. Harris’ campaign says her plan is an unprecedented federal investment in teacher pay. Harris promises to invest $315 billion over 10 years to give raises to teachers as well as to invest in programs dedicated to teacher recruitment, training and professional development. In new details released Tuesday, Harris’ campaign says the country has “failed to give teachers the respect and resources they deserve.” Harris’ decision to focus on teacher funding comes as many educators have walked out of their classrooms in protest, seeking higher pay and more education funding. It’s also an issue critical to the nation’s teachers unions, which have long been key players in Democratic politics.