> Additionally, the U.S. Constitution does not really permit blanket restrictions on employment for individuals.
As far as I know, blanket employment restrictions for individuals in the form of "will not do X for N years post-employment" have never been struck down under a U.S. constitutional rationale. Some states (such as California) ban or heavily restrict them, but federal law doesn't appear to.
It wouldn't be unconstitutional for private contracts, i.e. you can make any private agreement restricting your speech - but as a condition of being in public office.
As far as I know, blanket employment restrictions for individuals in the form of "will not do X for N years post-employment" have never been struck down under a U.S. constitutional rationale. Some states (such as California) ban or heavily restrict them, but federal law doesn't appear to.