Sunday on 'This Week': Rep. Tulsi Gabbard, John Hickenlooper, Rep. Seth Moulton, Gen. David Petraeus

Chief Anchor George Stephanopoulos sits down with 2020 presidential candidates Rep. Tulsi Gabbard, D-Hawaii, former Colorado Gov. John Hickenlooper and Rep. Seth Moulton, D-Mass., only on "This Week" Sunday.

Plus, "This Week" Co-Anchor Martha Raddatz goes one-on-one with former CIA Director Gen. David Petraeus on the latest tensions between the U.S. and Iran.

And the Powerhouse Roundtable debates all the week’s politics, with ABC News Chief White House Correspondent Jonathan Karl, former New Jersey Governor and ABC News Contributor Chris Christie, former North Dakota Sen. Heidi Heitkamp, and Democracy for America CEO Yvette Simpson.