Last Friday, former President Biden declared the Equal Rights Amendment "the law of the land" - so why has it failed to become the nation's 28th constitutional amendment.

U.S. President Joe Biden called the Equal Rights Amendment "the law of the land," on Friday, backing an effort to enshrine the change into the U.S. Constitution even though it long ago failed to secure the approval of enough states to become an amendment.

The remarks were largely a symbolic gesture of support for a century-long campaign to enshrine gender equality in the Constitution. But advocates said they could add heft to a future legal fight.