I'm kind of surprised congress didn't try to retroactively copyright the Declaration of Independence and Gettysburg Address and force textbook publishers to pay royalties.
Laws are protected by copyright and documents incorporated by reference into the law may be placed online.
The model building codes which are both incorporated by reference into many laws and are protected by copyright as model building codes, provided the test case.
Those were works made by the government, so they're automatically in the public domain. I don't see why you're against Mr. King having the copyright on the speech he wrote and gave?