Does the president Richard Nixon have the constitutional authority to break the law?

No, President Richard Nixon did not have the constitutional authority to break the law. The Constitution establishes that no one, including the president, is above the law. Nixon's actions during the Watergate scandal, including attempts to cover up illegal activities, ultimately led to his resignation as he was facing impeachment for violating legal and ethical standards. The principle of accountability applies to all branches of government, including the executive.