Come on, Get Happy  Early this summer, on the influential
NewsHour With Jim Lehrer, a leading pundit sat in front of TV
cameras and made the kind of broad pronouncement often favored
by media commentators. "American politics is about optimism,"
Mark Shields declared. "Americans are the most optimistic people
on the planet."  Uttered with great assurance, such statements
are more than silly. They sound like descriptions but function
as prescriptions. Claiming some extraordinary national trait -
in this case, depicting the USA as the global headquarters for
hope - these cheery proclamations end up instructing the public
as to proper attitudes.  That's hardly surprising when we
consider the sources. Shuttling between newsrooms and TV studios
while earning hefty salaries, big-name journalists are fond of
rosy windows on the world. Overall, the powerful politicians
they cover have similar vantage points. And when large numbers
of them get together, the upbeat - and facile - rhetoric is
thick.  A lot of speeches at