My comment: Why May 20? It turns out to be an event that happened after I left Taiwan and was not aware of until today. See
Taiwan Communique, Aug. 1988.
http://www.taiwandc.org/twcom/tc35-int.pdf
(starting page 8: The "May 20, 1988" Incident; Demonstration of farmers ends in confrontation)
(3) The following three reports talked about the same event at Heritage Foundation.
(a) 智库研讨五都选举 指选后为军售时机
http://www.voanews.com/chinese/news/20101202-TAIWAN-ELECTION-THINK-TANK-111214309.html
(b) William Lowther, Schriver urges US to engage with DPP. Taipei Times, Dec. 2, 2010.
http://www.taipeitimes.com/News/taiwan/archives/2010/12/03/2003490007
(Randy Shriver "said that Saturday’s voting suggested there was a possibility that President Ma Ying-jeou (馬英九) could be defeated in the 2012 presidential election and that the possibility 'should be taken seriously'”)
(c) 曹郁芬, 民進黨 重返華府政治雷達. Liberty Times, Dec. 3, 2010.
http://www.libertytimes.com.tw/2010/new/dec/3/today-fo1-2.htm
("民進黨兩年前輸掉總統大選後,各項相關研討會上,聽眾稀稀落落,不少美方人士甚至認為八年內民進黨都站不起來。如今美方人士不敢輕忽民進黨二○一二年重新執政的可能性,對蔡英文的領導路線,民進黨的中國政策和外交政策開始認真詢問")