Landgrebe was a stalwart defender of President Nixon throughout the Watergate scandal and during the Nixon impeachment hearings. When the House of Representatives voted to begin the impeachment hearings, 410 voted in favor and Landgrebe was one of the four who voted against. Even after the transcript of the "smoking gun" tape was released on August 5, 1974, documenting Nixon's complicity in the Watergate coverup, Landgrebe remained loyal and refused to listen to the tapes or read the transcripts. When asked about the damning tape transcript and the resultant rapid collapse of support for the president among Republicans in Congress and the likelihood that Nixon would be impeached, he said: "Don't confuse me with the facts. I've got a closed mind. I will not vote for impeachment. I'm going to stick with my president even if he and I have to be taken out of this building and shot." On August 9, 1974, when Nixon gave his televised resignation speech Landgrebe was one of 42 people in the White House during it. When the House of Representatives voted to accept the committee's report following Nixon's resignation it was 412 in favor and 3 against; the three opposed were Landgrebe, Otto Passman, and Sonny Montgomery. When the House voted on former New York Governor Nelson Rockefeller's confirmation as vice president to President Gerald Ford, he was one of 30 Republicans to vote against him due to his "extreme liberalism".