Well, to name a few:
- Officially collective but de-facto public/private hybrid ownership of all lands and products of labour
- Denizenship/citizenship duality; the former pays no tax but gets no free goods or services from the state
- Voting age lowered to sixteen; all citizens and denizens allowed to vote
- Ban of all business corporations and partnerships
- Some workplace compensation controls
- Guarantee of workplace democracy
- Economic cooperativization
- Tax code simplification and inclusion in Constitution to deter creation of new loopholes
- Right not to be executed, tortured, mutilated, conscripted, or enslaved
- Right for free speech not to be limited or censored by state
- Adjustment to and caveats for gun ownership rights
- Right for no person, social group, social status, or doctrine to be implied superior or inferior by the state
- Substantially expanded terms of state non-discrimination in regards to civil rights
- Marriage / civil partnership / civil union equality
- Right to trial over matters of controversy increase from $20 to $500 minimum, henceforth adjusted for inflation
- Right to adhere to own cultural identity (within certain limits)
- Right to basic income
- Right to primary and secondary education
- Right to adequate sanitation facilities
- Right to useful access to electricity and modern tools of communication
- Right to ample time off from work for sleep, leisure, and tending to other aspects of the good life
- Right to access medical facilities and social insurance covering health care expenses
- Right to be provided a passport without any fees
- Constitutional clauses advising the People of their duties to voluntarily accept, for the Revolution's survival
- Replacement of the House of Representatives with the People's Assembly
- Replacement of the Senate with the Continental Senate
- Altered responsibilities and checks on the legislative branch
- Replacement of the post of POTUS with an executive Presidium
- Fourth, technocratic branch of government drawing membership from academia
- Addition of a Constitutional Court to pro-actively uphold or nullify state acts and policies
- One-term limits in all branches of government; judges no longer have lifetime appointments
- Publicly financed elections, and public media outlets for covering elections and politics
- Proportional representation, different ballot and vote-counting method, and a lowered number of seats
- Territories allowed full-participation and seats in Congress
- Native nations guaranteed self-determination
- Compensation controls for elected officials
- Representatives cannot be expelled by Congress
- Open-list primaries for all parties fielding candidates for elected office
- Constitutional convention automatically re-convenes to debate amendments once every ten years
- Procedures for peacefully letting republics into and out of the Union
- Procedures for peacefully letting people into and out of the Union
- Change of national symbols; e.g. name becomes the American Federation of Socialist Republics
Personally, I think it would be easier to incorporate it all into a new Constitution rather than amend the old one.