John Erhlichman was President Nixon’s top domestic affairs advisor. Together with Nixon’s chief of staff, H. R. Haldeman, the two sought to protect the reclusive president, forming around him what others referred to as a “Berlin Wall.” Indeed, it was Ehrlichman and Haldeman who, in an effort to stop military information from leaking to the media, instructed Ehrlichman’s chief assistant, Egil Krogh, to oversee the “plumbers,” a secret group that undertook covert political operations. After Daniel Ellsberg secreted the Pentagon Papers to the New York Times, Ehrlichman instructed the plumbers to raid the California office of Ellsberg’s psychiatrist in search of incriminating evidence. Reporting on those efforts, Erhlichman tried not to reveal too much to the president. “We had one little operation. It’s been aborted out in Los Angeles which, I think, is better that you don’t know about,” he informed the president in September 1971.

After the Watergate investigation began, Nixon’s nominee for Director of the FBI, L. Patrick Gray, absorbed many of Congress’ blows during confirmation hearings. Subjected to heated criticism, especially over his relationship with the president’s legal counsel, John Dean, prospects for his approval looked bleak. Ehrlichman calculated political value in Congress eviscerating Gray’s nomination. It shifted the focus of Watergate from the White House. As Ehrlichman advised the president, better Gray be left “twisting, slowly, slowly in the wind.”

In April 1973, alienated from the White House by Nixon’s devotion to Haldeman and Ehrlichman and his own decision to freely testify before the grand jury and Senate committee, Dean implicated the president and his two advisors in the Watergate cover-up. On April 30, Nixon fired Dean and, following wrenching, emotional meetings with Ehrlichman and Haldeman, Nixon reluctantly accepted their resignations, along with the resignation of his Attorney General, Richard Kleindienst. Later convicted of conspiracy, obstruction of justice, making false statements, and other charges, Ehrlichman served eighteen months in federal prison.