In the poll, conducted in the days after the administration said it would extend sanctions relief to Iran in exchange for the country curbing its atomic program, 56 percent of registered voters said they supported the deal, up from 49 percent who backed it in August 2016 and 27 percent who OK’d it in August 2015. Roughly 3 in 10 (29 percent) remain opposed the deal.

Republicans registered the biggest uptick in support for the deal, which has been heavily criticized by GOP lawmakers since its inception in July 2015: 53 percent of Republican voters said they supported it, compared with 37 percent who backed it last summer and just 10 percent who supported it shortly after it was announced. Democratic support for the deal has been largely unchanged since August, and a larger share of independents are getting on board, from 41 percent in August to 48 percent now.