BEIJING — They protest, picket and sing to defend Mao’s memory, yearning for the East to be red again. But lately some of China’s Maoists are finding inspiration in an unlikely insurgent in the West: Donald J. Trump.

Mr. Trump “has torn up the old rules of the ruling elites, not just of the capitalist West,” said Zhang Hongliang, a polemicist who is the loudest proponent of what could be loosely called “Maoists for Trump.” In a recent essay, Mr. Zhang lauded the American president as being alone among national leaders daring “to openly promote the political ideas of Chairman Mao.”

President Xi Jinping of China will be sizing up Mr. Trump during a visit to his Mar-a-Lago estate in Florida this week, in the leaders’ first summit meeting. Meanwhile, many ordinary Chinese people have also been taking the measure of the new American president and have been bewildered, incensed and yet, sometimes, inspired.

The global wave of nationalist, anti-establishment sentiment that Mr. Trump rode to power has washed ashore in China, encouraging a hard-left fringe that is hostile to capitalism and Western influence, and that the Communist Party has long sought to cultivate — and contain.