BALTIMORE (WJZ) — The Iran nuclear deal is the focus of a major media campaign in Maryland. National groups are mounting an aggressive ad war in the state for and against the agreement. That’s because Senator Ben Cardin will play a pivotal role in whether the deal lives or dies.

Meghan McCorkell spoke to the senator.

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Millions of dollars have been spent on a massive ad campaign trying to sway undecided lawmakers–like Senator Cardin.

Competing ads are taking over Maryland airwaves. All of them are vying for one man’s vote.

Maryland Senator Ben Cardin is considered a vital vote on the Iran nuclear agreement.

“The bottom line–I need to know what’s in the best interest of this country in preventing Iran from becoming a nuclear weapons state,” he said.

The deal, supported by the White House, would curb Iran’s nuclear program in exchange for the U.S. lifting economic sanctions against the country.

The pro-Israeli group “J Street” will launch an ad campaign in Maryland Wednesday to try and convince Cardin to vote for the deal.

“We think it’s a strong deal, and it’s supported, as I said, by 60 percent of American Jews as well as by Americans at large,” said Dan Kalik, J Street.

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Some local groups are also pressuring the senator to vote down the agreement.

“We should all be real concerned about what may happen if this agreement is not strengthened,” said Dr. Art Abramson, Baltimore Jewish Council.

Abramson says it doesn’t go far enough to verify Iran won’t develop a nuclear weapon.

“They have consistently sponsored the worst terrorist groups. They have consistently killed Americans with that terror,” he said.

Senator Cardin says he’s still undecided.

“I’m not exactly sure yet when I’ll make my final decision,” he said.

Lawmakers will vote to approve or reject the deal next month.

On Tuesday, President Obama met with leaders in the American Jewish community to plead his case. He will address the nation Wednesday.

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Senator Cardin tells WJZ he spoke with Israeli Prime Minister Benjamin Netanyahu before the nuclear deal was reached. Netanyahu spoke out Tuesday against the agreement.