In 1968 he was re-elected, but the government declared the whole election invalid, and a military coup soon followed (see table). General Torrijos took power and dissolved congress, and Luis Chen found himself back at his job as a lawyer.
四年期滿，鄭仲衡於一九六八年順利蟬聯，沒想到那次選舉被政府當局宣佈無效。不久發生軍事政變（請參閱「巴拿馬政治年表」），軍事強人杜里荷上台，國會解散，鄭仲衡也就暫時回歸律師本業。