IT'S PAT :

On the Trail of Deep Throat (Rob Stafford, MSNBC)
Two more reasons that Patrick J. Buchanan makes a plausible Deep Throat : first, as I recall he was actually offered the job as head of the "Plumbers", but turned it down; and, second, the stated reason for his informing is that he was upset about the Nixon/Kissinger opening to China. If you combine the ethical considerations with the political considerations you have ample reason for someone to help bring Nixon down. An additional factor would be that Spiro Agnew, who was much more of a red meat conservative, would have taken over if Nixon had been brought down quickly.

UPDATE :
Multiple Tongues : Who Was Watergate's Deep Throat? John Dean Nominates Four Candidates. (Howard Kurtz, June 17, 2002, Washington Post

Posted by Orrin Judd at June 18, 2002 9:59 AM