In Wednesday’s briefings, House members asked the secretaries about the details of lifting an arms embargo on Iran and the fate of four American held captive in Tehran.

But few House members stayed for the entire briefing and dozens of them began filing out within a half-hour of walking in, suggesting that a room filled with hundreds of House members might not be the best place for Kerry, Moniz and Lew to make major inroads with undecided Democrats. Those Democrats still on the fence will ultimately decide whether to deny Republicans the veto-proof majority they would need to scuttle the nuclear accord between Iran and world powers.

Several Republican members said privately that Kerry was evasive and filibustered their questions, with Rep. Mike Pompeo (R-Kan.) charging that the secretary is not being forthright about a pair of nuclear documents that members in both parties are seeking from Kerry and the State Department says it doesn’t have.