STEVE INSKEEP, HOST:
Now, those who favor U.S. military intervention in Syria include backers of Israel. One of them is Republican campaign contributor Sheldon Adelson. Another is the American Israel Public Affairs Committee, or AIPAC.
NPR's David Welna reports on their lobbying efforts.
DAVID WELNA, BYLINE: Dick Durbin is the Senate's number two Democrat. According to the interest-group tracking website Maplight, he's also the sixth-biggest recipient in Congress of campaign contributions from pro-Israel political action groups. Like many other Democratic lawmakers who received such funds, Durbin cites Israel in explaining his support for military action against Syria, as he did earlier this week on the Senate floor.
SENATOR DICK DURBIN: When it comes to the nation of Israel, our closest and best ally in the Middle East, they understand what we are trying to do with chemical weapons in Syria, and they've made it clear through their friends in the United States and other ways, that they support it without fear of retaliation by Syria.
WELNA: That's the same kind of message lawmakers have been getting in person this week from some 300 persons associated with the pro-Israel lobby, AIPAC.
American University congressional expert James Thurber calls AIPAC one of Washington's top special interest groups.
JAMES THURBER: If you look at the support for Israel by the United States, they are a key part of that, they've been very successful on all the major issues related to Israel.
WELNA: AIPAC doesn't make campaign contributions - but it's seen to influence many pro-Israel groups that do. Thurber says most lawmakers' loyalty to Israel and its supporters has been a given - except when it comes to a military strike against Syria.
THURBER: They've voted with AIPAC, AIPAC gives them high ratings in terms of loyalty, but right now they're split, because their constituents are going in another direction.
WELNA: Indeed, as AIPAC's lobbyists swarmed Capitol Hill on Tuesday, Senate Republican leader Mitch McConnell - the third biggest beneficiary in Congress of pro-Israel contributions - announced on the Senate floor that the resolution the Foreign Relations panel approved last week authorizing military action against Syria, in his words: just doesn't pass muster.
SENATOR MITCH MCCONNELL: So I will be voting against this resolution. A vital national security risk is clearly not at play, there are just too many unanswered questions about our long-term strategy in Syria.
WELNA: McConnell is up for re-election next year in Kentucky, and Al Cross, a longtime political analyst from that state, says it's not surprising that McConnell chose to break ranks on this issue with his pro-Israel contributors.
AL CROSS: He's a party leader who wants to remain party leader, and his party is clearly - the majority of his party is against this and he faces an opponent in the primary who's against it.
WELNA: Number two Senate Republican John Cornyn, who's also seeking re-election, came out against the Syria resolution as well yesterday.
University of Chicago political scientist John Mearsheimer co-authored a book on the pro-Israel lobby's influence in Congress. He says AIPAC, which declined on-the-record interview requests for this report, is finding it has limited clout on Syria.
JOHN MEARSHEIMER: 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. 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.
WELNA: Even those lawmakers who do agree with AIPAC on Syria say its lobbying has not influenced them. Maryland Democrat Ben Cardin is a member of the senate panel that passed the Syria resolution last week.
SENATOR CARDIN: I voted before AIPAC took a position on this, so I have supported the resolution from the beginning.
WELNA: So too have most other congressional leaders from both parties. Still, American University's Thurber says there's a good reason why that resolution was pulled yesterday from the Senate floor.
THURBER: It looks like they're not going to get the votes, 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.
WELNA: Which would also be a rare outcome for AIPAC's lobbyists.
David Welna, NPR News, the Capitol.
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