Barney Frank, Dianne Feinstein Among May 13's Sunday-Morning News Show Guests

Well, if this didn't turn out to be a great week to be Barack Obama.

The President landed the campaign equivalent to an early-rounds left hook on all-but-default Republican challenger Mitt Romney this week when he announced in a "Good Morning America" interview with Robin Roberts that he now supports same-sex marriage legalization. Expect that topic exactly to dominate the conversations Sunday morning, judging from some of the scheduled guests across the board.

ABC's This Week

Obama's declaration should be covered from a number of angles, starting with openly gay longtime Massachussetts Rep. Barney Frank. Likely offering some perspective from the re-election campaign standpoint, Democratic strategist Hilary Rosen will throw in her two cents. They'll be joined by Rep. Marsha Blackburn (R-Tenn.) and Faith and Freedom Coalition chairman Ralph Reed.

NBC's Meet The Press

Sen. Carl Levin (D-Mich.) will be on NBC Sunday morning, along with Republican National Committee chairman Reince Priebus, Maryland Gov. Martin O'Malley and JP Morgan Chase CEO Jamie Dimon.

CBS' Face The Nation

Reed pulls double-duty and shows up on his second network of the morning, alongside Freedom to Marry president Evan Wolfson, singer and "American Idol" alum Clay Aiken, Massachussetts Gov. Deval Patrick, former Solicitor General Ted Olson, Republican strategist Mark McKinnon and Rep. Mike Rogers (R-Mich.).

CNN's State Of The Union

"State Of The Union" has a stacked lineup that starts with Sens. Dick Durbin (D-Ill.), John Cornyn (R-Texas) and Joe Lieberman (I-Conn.). Also joining will be Rep. Peter King (R-NY), Colorado Gov. John Hickenlooper, Family Research Council president Tony Perkins and American Values president Gary Bauer.

Fox News Sunday with Chris Wallace

Fox News trots out a short but interesting guest list. Wallace will be hosting Sens. John Thune (R-SD) and Dianne Feinstein (D-Calif.).