Well, there's another example. It was deliberately exploited by other lawmakers, but I imagine the original issue was probably accidental. The thirteenth amend

Well, there's another example. It was deliberately exploited by other lawmakers, but I imagine the original issue was probably accidental. The thirteenth amendment, while intended to abolish slavery, actually rendered state-sanctioned slavery explicitly constitutional (albeit, with extra steps); e.g. the Black Codes in certain states prohibited “vagrancy”, which (afaik) basically let them enslave anyone they could get a jury to agree wasn't “contributing to society” via “gainful employment”. This lead to the fourteenth amendment trying to patch this issue – not by forbidding slavery as punishment for a crime, but by requiring “equal protection”: in essence, states couldn't make laws that only applied to certain people. I don't have any examples of exploitable issues being deliberately introduced to legislation, because generally, people in a position to introduce them don't have to be subtle about it. Perhaps the 11th Congress of the Russian Communist Party's creation of the position of General Secretary was an example, but I don't know if we know what happened there. Before the thirteenth amendment to the US constitution, §4.2.3 permitted slavery and, arguably, implicitly required its enforcement even by states that outlawed slavery. That might count, seeing as many drafters were anti-slavery, and did not expect this clause to allow the 19th-century resurgence of slavery-powered plantations; whereas other drafters were pro-slavery, and presumably insisted upon this clause's inclusion.