Md. Sen. Ben Cardin Says He Will Vote 'No' To Iran Nuclear Agreement

WASHINGTON (WJZ) -- Maryland Senator Ben Cardin says he will vote "no" on the Iran nuclear agreement--a decision he calls a "vote of conscience."

Political reporter Pat Warren has more on Cardin's decision.

It's considered a setback for the Obama administration, but Cardin says he's voting according to what he thinks is best for the U.S.

Weeks flooded with ads directed right at him, face-to-face meetings, pressure from both sides. Maryland's Ben Cardin, the top Democrat on the Senate Foreign Relations Committee, votes "no."

In Baltimore Friday, Senator Cardin tells WJZ that there are clearly risks in both directions, but the risks are heavier going forward and trust has nothing to do with it.

"No. If it boiled down to trust, no one would go for any agreement with Iran," he said.

It's a split decision for Maryland: Maryland Senator Barbara Mikulski will vote "yes" for the deal, demonstrating what Senator Cardin has said all along--this is not a decision based on politics.

Warren: "You said at times you were second guessing yourself?"

Cardin: "I went back and forth. It's not a clear choice."

WJZ media partner The Baltimore Sun has Cardin discussing his opposition to the Iran Deal in this video.

WATCH: Ben Cardin Discusses His Opposition To Iran Deal

"It breaks down to preventing Iran from getting a nuclear weapon, not based on trust and the risks of moving forward, the risk of not moving forward. I just felt that if the strongest argument against opposing the resolution is what are the alternatives? It doesn't speak well for the agreement itself," Sen. Cardin said.

But the Senate Democrat "yes" list reached 38 Friday, and that protects the agreement from Republican efforts to kill it.

Senator Cardin is already working on legislation that would set up a policy assuring Iran will never be permitted to get a nuclear and puts all options on the table, including military options.

Senator Cardin's decision makes him one of only three Senate Democrats so far to disapprove of the agreement.