The president's visit falls on the 40th anniversary of Argentina's military coup that led to the so-called Dirty War. He has promised to declassify documents shedding light on what the U.S. knew.
His family said in a statement that Malik I. Taylor's death was the result of complications from diabetes.
President Obama said stopping attacks like those in Brussels is "difficult work." His advisers, he said, are working on "every strategy possible."
Author Elaine Kamarck explains superdelegates, the difference between caucuses and primaries, what happens in a brokered convention and how the rules of primaries can sometimes change.
Voter turnout was big in Idaho, Utah and Arizona, and that meant long lines at polling places. In Idaho, the line into one caucus site was reportedly longer than a mile.
Ex-Utah Gov. Mike Leavitt endorsed Ohio Gov. John Kasich for president, raising eyebrows because ex-Massachusetts Gov. Mitt Romney endorsed Texas Sen. Ted Cruz. But they say their aim is the same.
Trump is calling for torture "because we are in a political season," Walid Phares said, but in the White House "he's going to be tasking experts to answer that question."
Juan Zarate, senior adviser at the Center for Strategic and International Studies, talks about intelligence failures in the run-up to the blasts. Zarate is a former deputy national security advisor.
Belgians remain shocked and sad in the aftermath of the bombings. But King Philippe said they would respond to the terror threat with calm and dignity.
Sen. Angus King, of Maine, is in Europe with other members of the Senate Intelligence Committee members on a national security-focused delegation. The attacks in Brussels are now a top priority.