Hugh B. Brown was invited to give the keynote address at the Utah Democratic state nominating convention. He met with McKay and "asked if it would be in keeping with the policy of the Church and his office as an Apostle to accept the invitation." McKay responded: "Since some think we are one-sided in politics (having a member of the Twelve as Secretary of Agriculture during a Republican administration) it might be a good thing for him to accept this assignment and let the members of the Church know that both political sides are represented in the Church."
[Source: David O. McKay diary as referenced in Gregory A. Prince and Wm. Robert Write, David O. McKay and the Rise of Modern Mormonism. Salt Lake City: University of Utah Press (2005)]