MANILA, Philippines — Thousands of protesters marked Thursday’s anniversary of the 1972 declaration of martial law by late Philippine dictator Ferdinand Marcos with an outcry against what they say are the current president’s authoritarian tendencies and his bloody crackdown on illegal drugs. Hundreds of riot police were deployed to secure the marches and rallies, among the largest against President Rodrigo Duterte since he took power last year, although a new survey by the Washington-based Pew Research Center showed the president and his anti-drug campaign are widely popular in the Philippines. Pro-Duterte followers also staged rallies in Manila.