A Constitutional Convention can bypass Congress to draft new amendments, but they must still be ratified by the states like any other amendment.
Americans have a bizarre fear of amending the constitution. France has amended its constitution four times since 2000. Spain replaced its entire constitution in the late 70's and has since amended it twice. Canada rewrote its constitution in 1982 to add an amendment process and has since added 11 amendments. This same pattern can be seen around the world, with nations updating their constitutions nearly every year. Americans, on the other hand, tend to bizarrely see our constitution as a static and inviolate document that cannot be changed. This is humorous, in a way, as the constitutions drafters wrote a modification process right into the document and made it clear in their other writings that they expected it to be changed on a regular basis. If you told Thomas Jefferson that the constitution would only have 27 amendments after nearly 240 years, they'd probably have considered the amendment sections a failure and rewritten them.
Here's a few things that we could add in a Constitutional Convention:
- A new equal rights act
- Clarifying the meaning of the Second Amendment in a way that keeps assault rifles out of the hands of crazies.
- Make it clear that corporations are not people.
- Grant the federal government the power to impose laws on the states that don't require fantasticly wild interpretations of the Commerce Clause.
- Eliminate the electoral college.
- Impose proportional representation on a national level to break the two party system.
- Prohibit anyone who isn't an individual citizen from donating to politicians, to get corporate money out of politics.
A Constitutional Convention can propose ANYTHING. The question is, can that proposed amendment make it through 38 state legislatures? With at least 16 states demonstrating fairly consistent "blue state" leadership, you can be fairly certain that nothing too wild is going to make it into law. America won't have Christianity named as its national religion, slavery won't be reinstituted, and the federal government is not going to be crippled.