I think southern racist politicians frame their defense of racism  as “law and order” because it gives them a legitimate excuse to be racist. By presenting racism as “necessary” for maintaining societal order, these politicians are justifying institutionalized racism within the framework of the law, which makes it more difficult for people to challenge. While the landscape of American politics has evolved, the old southern strategy still affects American politics today because it set up a systematically racist government with people that are still stuck in old ways of thinking and enforcing law.