The right of informed decision in vital public policy issues. Johnson isn't a private citizen. He is currently the tipping point of half of the legislative body of the most powerful nation on earth in a time of war. Every American deserves to know if he is capable of doing his job for the next two years. Nations all over the world are making policy decisions based on what they think the U.S. Senate will be doing until 2008.
Imagine if Reagan's medical condition had been kept a closely guarded secret when he was shot?