A constitutional Amendment along these lines is needed:
1. The legislative function of the United States shall be performed directly by the people according to legislation that the people enact.
2. The right of citizens to directly vote for the laws under which they live shall not be abridged by the United States or by any State.
Why is this important?
Freedom and equality depend on each citizen having free and equal influence on the government they live under. The only way that is possible is for each citizen to vote directly on the laws and not for representatives that make and vote on the laws. See T. Paine and T. Jefferson statement on assosactualdemocracy.com.