SACRAMENTO, Calif. — In celebration of Dr. Martin Luther King Jr., more than 2,500 Californians marched through Sacramento’s Land Park neighborhood as part of the 42nd Annual March for the Dream. People of all ages — from infants to teenagers to grandparents — congregated at Sacramento City College and then poured into the streets during the largely joyous event. They carried banners and flags representing a myriad of organizations and causes, and they exuded joy, hope and passion. At the same time, there was an undercurrent of anger and frustration at injustices that still persist around the …