President Obama needs the votes of Democratic lawmakers like Connecticut Second District Congressman Joe Courtney if he expects to win congressional approval for the Iranian nuclear deal.

Once a district considered up for grabs and notorious for close elections, Courtney’s moderate politics, effectiveness in fighting to win submarine work for Electric Boat in Groton, and his frequent presence in the Second District's towns and cities has changed that perception. Democrats now view the Second as a safe district, at least as long as Courtney keeps running.

This means someone like Courtney has less to risk by supporting the deal and running afoul of the Israeli lobby and other opponents of the agreement, which is intended to prevent Iran from developing nuclear weapons.

Courtney is also a veteran member of the House Armed Services Committee, which will be reviewing the agreement. His backing of the deal could bring along other Democratic votes.

If the president cannot gain the support of someone like Joe Courtney, he and his deal are in trouble.

And as of now, Courtney is not committing.

In a statement issued after the Iranian agreement was announced last Tuesday, Courtney said it “establishes conditions to sharply inhibit Iran’s nuclear program,” calling it “a hopeful development in a region of the world that needs a new dynamic towards peaceful resolution of conflict.”

That all sounds very positive, at least from the perspective of the White House.

However, the congressman is not ready to sign on yet. He promised a “thorough review … to determine if it sufficiently monitors and contains any efforts by Iran to militarize its nuclear program, and maintains deterrents to prevent Iran from considering any straying from the agreement’s obligations.”

My reading is that the congressman is likely to back the agreement, but if the hearing process reveals serious problems with the ability to verify compliance, and political support for the deal badly erodes, Courtney is keeping his options open to bail.

On the Senate side, Sen. Chris Murphy appears to be a sure vote from Connecticut in favor of the nuclear arms control deal.

“The best way to stop Iran from obtaining a nuclear weapon is through diplomacy, not war,” said the Democrat, adding, “I congratulate President Obama, Secretary Kerry, and their team for the agreement that was reached today.”

More circumspect was Sen. Richard Blumenthal.

“While our common hope may be that diplomacy has succeeded in barring an Iranian path to nuclear-weapons capability, Congress must apply exacting standards and strict scrutiny, especially given Iran’s history of deceit and international law violations,” said Blumenthal.

If I were in the White House, I’d be nervous about getting Blumenthal’s vote.

And the president could well need every Democratic vote he can get. While it would be great to see the deal approved or rejected on the merits, the politics are thick. Republican lawmakers don’t want to face a primary in which they confront charges from a challenger that they supported Obama in betraying Israel and kowtowing to Iran.

Many Democrats facing close elections in 2016 will have the same fear of facing such attacks from a Republican in the general election.

Such political calculating blithely ignores the troubling reality that a congressional rejection would leave a military attack as the remaining option to try to block Iran from getting the bomb, which in turn could trigger a broader war across the Middle East.

Interestingly, a former senator from Connecticut could also play a part in how things play out. The hawkish Joe Lieberman, who ran as the vice presidential candidate on the Democratic ticket in 2000, only to later reverse course and support Republican presidential candidate Sen. John McCain in 2008, will be seeking Democratic votes to kill the deal.

“There is much more risk for America and reward for Iran than should be in this agreement. It is not the good deal for America we all wanted,” he said Tuesday during congressional testimony. The former senator went on to say the inspection provisions “fall far short, dangerously short.”

The president’s best prospects may be a rejection by the House and Senate, but with enough Democratic support that his veto cannot be overridden, leading to backdoor approval. Whatever happens, Connecticut Democrats could play a significant role.

Paul Choiniere is the editorial page editor.

Twitter: @Paul_Choiniere