JUDY WOODRUFF: It's five days until the Wisconsin primary, and rivals in both parties are turning up the heat on Donald Trump.
After a rough 24 hours, the Republican front-runner stayed mostly out of the public eye today.
Off the campaign trail, Donald Trump spent his day at meetings in Washington. One was with his foreign policy team, a day after he refused to rule out a nuclear strike against Islamic State militants.
CHRIS MATTHEWS, MSNBC: Can you tell the Middle East we're not using a nuclear weapon on anybody?
DONALD TRUMP (R), Republican Presidential Candidate: I would never say that. I would never take any of my cards off the table.
CHRIS MATTHEWS: How about Europe? We won't use it in Europe?
DONALD TRUMP: I — I'm not going to take it off the table.
CHRIS MATTHEWS: You might use it in Europe?
DONALD TRUMP: No.
JUDY WOODRUFF: In fact, U.S. presidents by tradition do not rule out the use of nuclear weapons.
In that same televised town hall, Trump also said women who have abortions should be punished if they're ever made illegal. Later, in a new statement, he said the physician, not the woman, should face penalties.
Today, Republican rival John Kasich pounced as he campaigned on Trump's home turf, New York City
GOV. JOHN KASICH (R-OH), Republican Presidential Candidate: He becomes unmoored and then has to spend a lot of time trying to figure out how to correct all the mistakes that he made. And I have to tell you that, as a commander in chief, and leader of the free world, you don't get do-overs.
JUDY WOODRUFF: In Purchase, New York, the Democratic front-runner, Hillary Clinton, zeroed in on the abortion comments.
HILLARY CLINTON (D), Democratic Presidential Candidate: You know one of my favorite Americans, Maya Angelou, said, when someone shows you who they are, believe them.
HILLARY CLINTON: Donald Trump is showing us exactly who he is, and we should believe him.
JUDY WOODRUFF: Clinton's rival, Bernie Sanders, took on Trump's comments indirectly in Pittsburgh.
SEN. BERNIE SANDERS (VT-I), Democratic Presidential Candidate: All of you are aware of Republicans running all over the country talking about family values. And what they mean is no woman in this huge room, in this state, in this country should have the right to control her own body. I disagree.
JUDY WOODRUFF: For all of the candidates, the next big day of reckoning looms Tuesday, in primaries in Wisconsin.
We will talk with one of Donald Trump's main foreign policy advisers right after the news summary.