Complex sentence: He is the president and CEO of Raynard Jackson & Associates, LLC (RJA), a government relations and public relations firm based in Washington, D.C. They not only work with politicians, but also represent professional athletes and entertainers.
Split into simpler sentences: He is the president and CEO of Raynard Jackson & Associates, LLC (RJA). This is Government Relations and Public Relations firm based in Washington, DC. They not only work with politicians, but also represent professional athletes and entertainers.