On Jan. 5, Juan Guaidó was expected to be re-elected as the head of Venezuela’s National Assembly, which is the only democratic and internationally recognized institution left in the country. Instead, allies of President Nicolás Maduro staged a fake speaker election with his allies to oust him. That is why Mr. Guaidó’s climbing the building’s iron gates after being barred entry by a human barricade of National Guard members was nothing short of heroic.

Mr. Guaidó, who was elected president of the assembly a year ago and is recognized as Venezuela’s interim president by 60 countries, remains powerless despite overwhelming international and domestic support. But the most striking aspect of Mr. Guaidó’s precarious balancing act atop the gates of the legislative palace is the realization that the opposition is closest to attaining political change when it remains defiant, but within the limitations established by the Venezuelan Constitution. In the past when the opposition has explored riskier and less democratic alternative paths to precipitate a political transition, the outcome has been elusive.

After he was blocked from entering the National Assembly’s building, Mr. Guaidó held a vote at the headquarters of the opposition-linked newspaper El Nacional, where he was ratified to his post by 100 out of 167 legislators. The roll call was carefully registered to abide by the rules established by Congress and the Constitution.