Frank Sesno - It is a vastly diminished role. Because of social media, the Internet, the explosion of cable channels and the disaggregation of the audience (with a lot less 'brand' loyalty), the once-dominant role of the White House press corps is a shadow of its former self. Presidents routinely go on cable shows, comedy shows, late night shows, podcasts. Obama famously sat for an interview with Zach Galafianakis for his "Between Two Ferns" interview internet program, which is said to have had more than thirty million views. Obama did a garage interview with comedian Marc Maron for his irreverent "WTF" podcast. He has also appeared in Google town hall meetings and in interviews on Comedy Central. This is very deliberate niche targeting by the White House. Where once these interviews would have mostly gone to White House reporters, they are now dispersed and the White House press corps covers them like they once covered major speeches at universities or national parliaments.
Furthermore, the White House press corps now enjoys much less profile and prestige than it once did. The prime-time East Room presidential news conference is long gone, and the stature and profile of White House correspondents has declined along with the ratings and the circulation of major networks and publications that have a seat in the Press Room.
All of this being said, the White House press corps is still remarkably influential and important, due to their proximity to the president, their familiarity with and access to his top advisers and their understanding of both politics and policy. These reporters remain well connected, highly competitive and the daily driver of White House coverage.