When a politician stresses a particular issue (corruption, poverty, illegal immigration, and so forth), what do you call it? I considered 'talking point', 'selling point', 'agenda', but none of them seems to fit. For example
Racial inequality has become the candidate's prime _________ during the congressional campaign.
I guess you could say 'point of agenda', but I don't like it. It's like I forgot some natural way of saying it.