If Senate Democrats can amass 41 votes in favor of the deal, they could block passage of a congressional resolution to disapprove of the deal.
If that doesn’t happen and the Republican-led Senate votes to disapprove of the deal, President Barack Obama has vowed to veto it. Democrats then would need 34 votes — four more than they have now — to prevent a congressional override of the presidential veto.
A vote on the nuclear deal the U.S. and other world powers negotiated with Iran is scheduled for early September.
“This next week or 10 days will be critical because those that have really been thinking over long and hard about where they’re going to end up, many of them are likely to announce something before we return from the Labor Day recess,” Durbin said in an interview with The Associated Press.
He wouldn’t predict the success of getting to 34 or 41 votes, but said some of the 14 undecided Democrats likely would announce their decision before Congress returns from its August recess.
Republicans are unanimously against the deal which provides sanctions relief to Iran in exchange for constraints on its nuclear program. Two Senate Democrats also have announced their opposition.
In an opinion piece in The News Journal of Wilmington, Delaware, Carper said the deal was good for America and allies, including Israel.
“The stakes surrounding this deal couldn’t be higher,” Carper wrote. “Current estimates assess Iran’s nuclear program to be as close as two months away from a bomb. Without a deal, that time will only shrink. That’s a stark comparison to what the deal would yield – an Iranian nuclear program that is at least a year away from a bomb for each of the next 15 years and, possibly, longer.”
Associated Press writer Deb Riechmann contributed to this report.