This morning NPR’s David Welna reports, Pro-Israel Lobby Finds Longtime Supporters Defect On Syria , on AIPAC’s influence in Congress during this rare instance the lobby is fighting an uphill battle over the proposed U.S. attack on Syria. Here’s a clip:

AIPAC’s lobbyists swarmed Capitol Hill on Tuesday, Senate Republican leader Mitch McConnell — the third biggest beneficiary in Congress of pro-Israel contributions — went to the Senate floor to announce that the resolution the Foreign Relations panel approved last week authorizing military action against Syria did not pass muster. “So I will be voting against this resolution. A vital national security risk is clearly not at play,” McConnell said, adding, “there are just too many unanswered questions about our long-term strategy in Syria.”McConnell is up for re-election next year in his home state of Kentucky. Longtime Kentucky political analyst Al Cross isn’t surprised by McConnell’s decision to break ranks on this issue with pro-Israel contributors. “He’s a party leader who wants to remain party leader, and his party is clearly, the majority of his party is against this,” says Cross, “and he faces an opponent in the primary who’s against it.”

Number two Senate Republican John Cornyn, who’s also seeking re-election next year, has also come out against the Syria resolution.

University of Chicago political scientist John Mearsheimer, who co-authored a book on the pro-Israel lobby’s influence in Congress, says AIPAC has limited clout on Syria. “It almost always gets its way on issues like the Israel-Palestine conflict, on foreign aid to Israel, and on protecting Israel in the United Nations,” he says. “But when it comes to pushing the United States to use military force against another country because it’s seen as being in Israel’s interest, the lobby does not always get its way.”

…….. American University’s Thurber says there’s a good reason why that resolution was pulled yesterday from the Senate floor. “It looks like they’re not going to get the votes,” says Thurber, “and so it is something, at least on this issue, that’s rare, that you have all those people together, and rare that it looks like they may lose.”

And that would also be a rare outcome for AIPAC’s lobbyists.