Emphasis mine.
You need to distinguish between laws and constitutional amendments. We do not change the Constitution by passing laws; we change the Constitution by amending the Constitution.
If Congress were to pass a law that banned all political speech on street corners, that law would be found in violation of the First Amendment, and thus would be found unconstitutional.
But if two-thirds of each House of Congress were to pass a constitutional amendment banning political speech on street corners, and then three-fourths of the states were to ratify that amendment, then the amendment would become a part of the Constitution, and would effectively override some of the free expression provided for in the First Amendment.
Also, your observation about women and the vote is incorrect. The fact that women were asking for the right to vote was NOT unconstitutional. In fact, the first amendment itself gave them every right to ask for, and even demand, the vote.
Also, before the 19th Amendment was ratified in 1920, there was nothing unconstitutional about women voting. In fact, by the time the amendment passed, a large number of states already allowed women to vote. Here in California, for example, women’s suffrage was granted in 1911.
Before the 19th Amendment was passed, there was nothing in the Constitution forbidding states from denying women the vote because they were women. Some states, by the end of WWI, still chose to exercise this option and deny women the vote. What the 19th Amendment did was make it unconstitutional to deny anyone the vote of the grounds of their sex.