Louisiana senator on voting against the War Powers Resolution

WASHINGTON (CBS, KYMA) - Face the Nation moderator Margaret Brennan spoke with Sen. Bill Cassidy (R-La.) Thursday in his first U.S. network interview after he reversed his position on a War Powers Resolution, voting against it, and delivering President Donald Trump a victory.

The Senate blocked the resolution, which would have required congressional approval for continued U.S. military involvement against Iran, 50-47 Wednesday night.

The vote came amid ongoing debate over the Trump Administration's handling of Iran following recent military strikes and a ceasefire agreement.

In the interview, Sen. Cassidy explains his reversal just a day after he and the president got into a shouting match at a Senate GOP meeting on Wednesday.

"If the original objections were to destroy, degrade, if you will, Iran's nuclear capability, their ability to do a ballistic missile, and their conventional warfare capability, and we were supposed to be out of there in four to five weeks with maybe a little bit of a sprinkling of regime change, that's how it came across. The regime change is off the table, that doesn't seem as if that's going to happen, but it does seem as if the way they laid it out, the other three objectives can be reached, and with those other three objectives- now we have to trust but verify, but as they laid it out, they have a plausible plan by which to achieve those, and that's what I was interested in."

Sen. Bill Cassidy (R-La.)

Other topics in Brennan's wide-ranging interview include Cassidy's primary loss to Julia Letlow, what he hopes to accomplish in the next seven months as a senator, and concerns he has with the Trump Administration's Make America Healthy Again public health policies.

You can watch more of Brennan's interview with Cassidy on Face the Nation Sunday on CBS, and the full conversation will be posted to YouTube and CBSNews.com.