President Obama’s sweeping changes to Cuba policy are expected to dominate the Sunday talk shows this week, with one of the harshest critics of the president’s efforts to normalize diplomatic relations — Sen. Marco Rubio (R-Fla.) — appearing on each of the broadcast networks’ telecasts. Obama will have a chance to defend the policy himself in a rare Sunday show appearance, sitting down with Candy Crowley for her last episode as host of CNN’s “State of the Union.” The veteran political correspondent is leaving the network after 27 years.