When, in 1958, the Nixons were about to go on a multination tour of Latin America, Pat Nixon called Mollie Parnis, a prominent dress designer who catered to the wives of many of Washington and New York’s most powerful men, including Mamie Eisenhower, about doing some clothes for her. Ms. Parnis mentioned this to Mamie Eisenhower, who immediately vetoed the idea. “No, no, dear, don’t do that. Let the poor thing go to Garfinckel’s and buy something off the rack.”