When the executive branch doesn't agree with the law, one tool they have as a separate branch of government is to not enforce the law. In U.S. political history

When the executive branch doesn't agree with the law, one tool they have as a separate branch of government is to not enforce the law. In U.S. political history, President Andrew Jackson reportedly responded: "John Marshall has made his decision; now let him enforce it!" referring to the Supreme Court ruling in https://en.wikipedia.org/wiki/Worcester_v._Georgia https://en.wikipedia.org/wiki/Worcester_v._Georgia.