Valarie Kaur on the power of love as a force for social change on Martin Luther King Jr.’s Day. Plus, The downfall of Duncan Hunter, the Hunter political dynasty and the race to replace him has now been turned into a documentary. Also, meet the candidates vying to be the next San Diego mayor — two establishment Dems, an outsider and the lone Republican. And, in a new episode of “Only Here,” meet the entrepreneur who is trying to tame the San Diego-Mexico border-crossing wait time with technology. Finally, Emmy-winning actor Alan Alda is partnering with the Scripps Research Institute to improve how scientists communicate their findings to the general public.