Leading lawmakers on the Senate Foreign Relations Committee appear to have reached a compromise to dilute some provisions of major Iran legislation ahead of this afternoon’s markup. The announcement came on the heels of a direct appeal to senators from Secretary of State John Kerry and Energy Secretary Ernest J. Moniz, who visited Capitol Hill this morning to chip away at the legislation’s chances of securing a veto-proof majority. Among the anticipated changes to the bill would be removing controversial language that tying Iran’s continued support of terrorism to receiving relief from congressional sanctions as part of a final international nuclear agreement. That certification requirement drew particular ire from Democratic lawmakers and the White House. Sen. Bob Corker of Tennessee, who leads the Foreign Relations Committee, told reporters his sense is “we’re moving toward a strong support in committee, but again in this business you never count your chickens before they hatch.”