Some 1.5 million Iranian-Americans live in the United States and 85 percent of them are citizens.
Morad Ghorban, Policy Director for the Public Affairs Alliance of Iranian Americans (PAAIA), says polls show that Iranian-American support for President Obama is down 10 points from 2008, when he first ran, mostly because of his policies toward Iran.
"When you look at party identification and affiliation it seems like President Obama will still get the majority, if not the plurality, of Iranian-Americans in this election," he said. "Fewer Iranian-Americans today approve of Obama's handling of the Iran issue in his foreign policy than they did in 2009, but the majority, about 55 percent, say they intend to vote for him."
Less support for Obama does not translate into more backing for Mitt Romney. A 2012 poll by Zogby Research Services showed only 13 percent of Iranian-Americans are Republicans.
Behnam and Arian (who don't want their full names used) are younger U.S. citizens eligible to vote, just like the vast majority of Iranians in the United States. They say the tensions between Tehran and Washington, and the perceived threat of possible military action against Iran, have influenced their thoughts on the election.
"This issue has a major effect on their psyche. The question of whether or not there will be war on their native land where relatives still live, and [they] wonder if all the places their loved ones routinely gather around will continue to exist," said Behnam.
Arian won't vote for Romney; he thinks a Republican administration is more likely to support military action against Iran.
"It's hard," said Arian. "Even if you know that some action needs to be taken, it's hard to side with the party that you know is more inclined to engage in military action against them or be more ready to take part in that."
But many Iranian-Americans see little real difference between Obama's Iran policy, and Romney's, making it difficult to determine how and why they will cast their ballots.
"There's a bit of a difference, but in my opinion the difference is in the language, the rhetoric," explained Behnam. "Is it in the execution? No."
Behnam says he is not voting for either candidate on Tuesday. He is not alone. Polls say nearly 30 percent of Iranian-Americans eligible to vote plan to say home on Election Day.