Sunday Breakfast Menu, June 30 With the exact whereabouts of Edward J. Snowden unknown, Julian Assange, the founder of WikiLeaks, will join ABC's "This Week" on Sunday to discuss how his antisecrecy group has helped Mr. Snowden in the wake of his disclosures about the National Security Agency. In the aftermath of the Supreme Court's decisions on the Defense of Marriage Act and California's Proposition 8, the Sunday shows will feature figures on both sides of the debate over same-sex marriage. On CBS's "Face the Nation," Theodore B. Olson, the conservative lawyer who challenged Proposition 8, and Tony Perkins, the president of the Family Research Council and an opponent of same-sex marriage, will discuss the outcomes. Mr. Olson's co-counsel, David Boies, will appear on CNN's "State of the Union" to weigh in on the case. In addition to Mr. Assange, ABC will have interviews with Chad Griffin, the president of the Human Rights Campaign, and Brian S. Brown, the president of the National Organization for Marriage. And Representative Tim Huelskamp, the Kansas Republican who says he will introduce a constitutional amendment to restore the Defense of Marriage Act, will be on NBC's "Meet the Press." Last week also saw the Senate approve a significant overhaul of the nation's immigration system. As lawmakers look ahead to the challenge of getting the legislation through the House, "Fox News Sunday" will talk to Senator John McCain, Republican of Arizona, and Senator Charles E. Schumer, Democrat of New York, who helped usher the bill through the Senate. Also on the program will be Representative Trey Gowdy of South Carolina, chairman of an immigration subcommittee, and Representative Mario Diaz-Balart, Republican of Florida and a member of the House group working on immigration reform. Representative Nancy Pelosi of California, the House Democratic leader, will join NBC to discuss the bill's prospects in the House, as well as the Supreme Court's decisions on same-sex marriage. Representative Robert W. Goodlatte of Virginia, chairman of the House Judiciary Committee, and Representative Luis V. Gutierrez, Democrat of Illinois and chairman of the Congressional Hispanic Caucus's task force on immigration, are scheduled to appear on CNN to talk about immigration. Mr. Goodlatte will also join Bloomberg's "Capitol Gains" at noon Eastern. State Senator Wendy Davis of Texas, who made headlines last week for staging an 11-hour filibuster to fight a bill restricting abortion rights, will tour the shows on Sunday, visiting the programs on ABC, CBS and NBC. Also on CBS: Gen. Michael V. Hayden, who served as director of the N.S.A. under George W. Bush. Telemundo's "Enfoque," which airs at noon Eastern, will have a packed program on immigration with Senator Marco Rubio, Republican of Florida and a key player in getting the bill through the Senate; Senator Robert Menendez, Democrat of New Jersey and another member of the group that worked on immigration; Representative Ileana Ros-Lehtinen, Republican of Florida and chairwoman of the House Foreign Affairs Committee; Mr. Gutierrez; and Cecilia Muñoz, President Obama's chief domestic policy adviser. Mr. Menendez will also appear on Univision's "Al Punto" at 10 a.m. In addition to Fox, Mr. Diaz-Balart appeared on Bloomberg's "Political Capital" on Friday along with Ms. Muñoz. Representative Michael McCaul, Republican of Texas and the chairman of the Homeland Security Committee, will join C-Span's "Newsmakers" to talk about topics including border security and the N.S.A.