Last week’s controversial speech by Israeli Prime Minister Benjamin Netanyahu was the latest salvo in a long-running battle between President Obama and the U.S. Congress over efforts to craft a deal with Iran over its nuclear program. Members of both parties have been skeptical of the administration’s approach, and have pressed for congressional approval of any eventual agreement before sanctions against the Islamic Republic are lifted.

Crippling sanctions on Iran’s oil exports have given the Obama administration leverage to press for a nuclear accord, while seeing them lifted is the Iranian government’s prime motivation for agreeing to talks. With the deadline to reach a deal having been extended to June, it remains to be seen what role Netanyahu’s visit will play in shaping public perception. While more than 60 percent of the American public supports an agreement with Iran that allows some nuclear enrichment, Congress has taken a much harder line, and it it is unclear how effective the president will be at selling whatever deal is eventually reached.