<p>WASHINGTON, Feb. 16 - It was no accident that PBS found itself turning to Elmo, the popular "Sesame Street" character, to lobby on Capitol Hill this week. There were not many options.</p>
<p>Public television is suffering from an identity crisis, executives inside the Public Broadcasting Service and outsiders say, and it goes far deeper than the announcement by Pat Mitchell that she would step down next year as the beleaguered network's president.</p>