Sentence:  By the time politicians in several cities backed down on Tuesday and announced that they would cut or consider reducing fares, the demonstrations had already <WSD>morphed</WSD> into a more sweeping social protest, with marchers waving banners carrying slogans like “The people have awakened.” 
Meaning of the word marked with <WSD> tags:  To undergo dramatic change in a seamless and barely noticeable fashion.