Bob's Blog: Amtrak crash, 2016 race, foreign affairs

After this week's horrific Amtrak crash, many are wondering what needs to be done to prevent future incidents. And the incident sparked a debate on Capitol Hill over funding for Amtrak and other infrastructure.

We'll get the very latest on the investigation, which so far has focused on the high speed of the train. First we'll talk to Robert Sumwalt of the National Transportation Safety Board, which is investigating the deadly incident. And we'll also talk to Sen. Bob Casey Jr., D-Pennsylvania, who has visited the crash site.

Turning to the 2016 presidential campaign, we'll talk to Wisconsin Gov. Scott Walker. He just returned from a trip to Israel and is trying to brush up on foreign policy ahead of a likely presidential campaign. He's doing well in the polls right now, but can he hold his position near the top of the pack? And what does he have to say about the big issues of the day - Iran and ISIS, immigration, and much more.

Later in the program, we'll sit down with Rep. Devin Nunes, R-California, the new chairman of the House Intelligence Committee, for his first Sunday show interview in his new role.

Also, we'll sit down with former Secretary of Defense Robert Gates. He served under President Bush and President Obama - what does he have to say about our current challenges? Is President Obama weakening our alliances with traditional partners like Israel and Saudi Arabia? We'll talk to Gates about a range of issues from Williamsburg, Va., where he is the chancellor at the College of William and Mary.

As always, we'll round out the show with our panel of experts. This week, we'll talk to Peggy Noonan of The Wall Street Journal, David Ignatius of the Washington Post and Frank Rich of New York Magazine.

We hope you'll join us this Sunday. Check your local listings.