But when China invited Mr. Li to tour the mainland this week, the Communist Party got a taste of its rival's pungent democracy.
During an address at Beijing University on Wednesday evening, broadcast live on a cable television network, Mr. Li chided China's leaders for suppressing free speech, ridiculed the university administration's fear of academic debate and advised students how to fight for freedom against official repression.
"All over the world leaders have machine guns and tanks," Mr. Li told the students and professors in the packed auditorium. "So I'm telling you that in the pursuit of freedom, you have to be smart. You have to use your cunning."
Mr. Li, 70, is a member of Taiwan's Parliament and the host of a popular talk show on the mainland-backed Phoenix TV of Hong Kong, which helped arrange his trip to China. It is his first visit since his family fled the mainland for Taiwan when he was a high school student.
China invited Mr. Li as part of its effort to court Taiwan notables who are steadfastly opposed to President Chen Shui-bian's efforts to move the island toward formal independence. This spring the Chinese president, Hu Jintao, also rolled out the red carpet for three Taiwanese opposition party leaders, an overture that helped to soften support for Mr. Chen's agenda.
Mr. Li does not have a high profile in Taiwanese politics, but he has an outsize reputation among intellectuals in China for his prolific writings - he has written nearly 100 books - and his fervent belief that Taiwanese should be proud to be part of greater China.
He challenged the Nationalists when they governed Taiwan as a one-party state and served time in prison in the 1970's for dissent. When Taiwan became a democracy, he attacked those who supported separatism. He ran for president in 2000 on a platform of unification with China, supporting its government's vision of "one country, two systems."
But when he arrived in China, he surprised his hosts with caustic comments aimed not at Taiwanese separatism but at mainland authoritarianism.
Though Mr. Li did not criticize President Hu directly, he made pointed references to the lack of freedoms in China and suggested that the "poker-faced" bureaucrats of the Communist Party did not have enough faith in their legitimacy to allow normal intellectual discussion.
With several top university officials sitting by his side, he called the administrators "cowardly" for ferreting out professors at the school who were suspected of opposing Communism.
He said even the warlords who ran China prior to the rise of the Nationalists in the late 1920's had the wisdom to select a noted educator, Tsai Yuan-pei, to run the university, which became China's foremost institution of higher learning at that time.
He also praised the scholar Hu Shih for defining what it means to be a liberal.
"A group of slaves will never make a liberal and progressive country," he quoted Mr. Hu as saying. "Such a country can be made up only of independent minded and free-thinking people."
Though his arrival in China was covered prominently by the state-run media and his speech was viewed on television by millions around China, propaganda authorities imposed a blackout on reporting about his visit after the speech. A commentary carried by the New China News Agency on Thursday said his speech "had not passed the test."
Mr. Li joked after his speech that he anticipated a negative reaction, predicting that he might see the inside of Qincheng, China's most notorious political prison, before he could see Changcheng, the Great Wall.