Louisiana voters have approved a constitutional amendment to strengthen already strong gun possession rights in the state. The amendment was drawn up to eliminate language in the Louisiana Constitution that would allow passage of laws prohibiting concealed weapons. It also includes a requirement that any gun restriction laws be held to a tough judicial standard. Opponents said the measure could spell the end to gun prohibitions on college campuses, churches and government buildings, while opening a door for criminals convicted of gun-related crimes to appeal their court cases. The issue was 1 of 9 proposed constitutional changes on Tuesday's ballot.