1959 saw massive Civil Rights marches (including one by MLK to Washington) and confrontations, so bad that Eisenhower tried to get a civil rights bill passed.
Running this PSA was both courageous and pandering. Most Southern parents would have violently rejected it if they knew their kids had brought it into the house. Yet most of the media tried to appear as if they were on the side of good, and it helped to be able to say they were supporting the president. Equality was still the American ideal in theory. As long as it didn’t happen on their block.