Rep. Dan Kildee, D-Mich., marched onto the House floor Thursday night, earnestly seeking support from as many colleagues as he could  find on an issue beholden to no party line.

Armed with a one-paged pamphlet slightly larger than a post card, Kildee passed out information on an American from his district who has been held prisoner in Iran for the past two years.

That prisoner, Amir Hekmati, a 29-year-old former Marine, was arrested in Iran in 2011 while visiting his grandmother. 

He was detained on charges of spying for the CIA and sentenced to death. 

Hekmati's confession was aired on state-run TV in Iran, a confession his family says was clearly coerced. The death sentence has since been annulled but Hekmati remains locked up, imprisoned now for more than 640 days without access to a lawyer or consular officials.

"What if this was your son, all alone," Kildee pleaded with his colleagues. "There's a lot of frustration here about gridlock, but saving this life, that's something we can all rally behind."

The congressman's plan is simple. He's asking his colleagues to take a picture holding a "Free Amir" sign in front of them. 

On Monday the pictures will be posted on Twitter accompanied with #FreeAmir. 

"The response has been overwhelming," a Kildee spokesman told Fox News. "We've just started and we already have pictures from 75 Members spanning the political spectrum." 

Reps. John Lewis, D-Ga.,  and Darrel Issa, R-Calif., were two of the first to join the campaign. 

Kildee's office says they are now getting about 10 pictures an hour.

This is not the first time Kildee has pushed for Hekmati's freedom. 

In July, he sent a letter to Secretary of State John Kerry that was signed by more than 100 members of Congress. In it, Kildee asked the State Department to raise the profile of the case and "explore all options to secure Hekmati's release."

United States Ambassador to the United Nations Samantha Power has also been asked to help

. In response, she tweeted, "Those missing or unjustly detained, including Amir Hekmati...must be returned home. #Iran."

The timing of the new "Free Amir" social media campaign is not coincidental. 

On Thursday, the White House signaled a meeting between President Obama an Iran's new President Hassan Rouhani may take place at next week when the United Nations General Assembly convenes in New York. 

It would be the first between U.S. and Iranian presidents since the 1979 Islamic Revolution and comes on the heels of Rouhani calling for "constructive" dialogue to end "unhealthy rivalries."

"The world is watching," Kildee said. "If Iran wants to take a productive step toward re-engaging with the international community - this is it."