“Richard Nixon’s crimes were committed purely in the interest of his own political gain,” Mr. Wallace told Mr. Howard before an audience of a few hundred after viewing the filmmakers new film “Frost/Nixon,” which is about the only U.S. president to resign from office.

“I think to compare what Nixon did, and the abuses of power for pure political self preservation, to George W. Bush trying to protect this country — even if you disagree with rendition or waterboarding — it seems to me is both a gross misreading of history both then and now,” Mr. Wallace said.