Maybe I can explain it to you. This is really about two conflicts.
(1) The conflict between the two Israeli lobby groups, AIPAC and J Street.
(2) The conflict between two foreign policy groups in the GOP, Realists and NeoCons.
J Street is not an anti Israel group. They disagree with AIPAC as to what course Israel should take to secure Israel. AIPAC has been around for a long time, is very large and wealthy, and have a lot of influence. They give a lot of campaign money to NeoCon Republicans such as senators Tom Cotton and Mark Kirk. They also give a lot of money to Liberal Interventionists democrats like senators Robert Menendez and Chuck Shumer.
J Street is very young and don't have nearly as much money or influence and they tend to give their campaign money to Realists like republican senator Bob Corker and democrat senator Diane Feinstein.
James Baker is a very prominent foreign policy realist. If you were to make a list of "Wise Old Realists" that list would include republicans Henry Kissinger, Brent Scowcroft, James Baker, and George Schultz, plus democrats like Zbigniew Brzezinski, Sam Nunn, and Lee Hamilton. In fact the Iraq Study Group was co-chaired by two wise old realists, Baker(R) and Hamilton(D). And two very prominent realists served on the Iraq Study Group and both would serve as Sec of Defense(Bob Gates(R) and Leon Panetta(D). The Iraq Study Group served to knock 3 prominent NeoCons from their positions of power under GW Bush. Doug Feith the defense undersecretary for policy, Paul Wolfowitz the deputy sec of defense, and the defense secretary Don Rumsfeld. When Bush fired NeoCon Rumsfeld, he first offered the job to Realist James Baker who turned him down so Bush then offered the job to Realist Bob Gates, who accepted and was retained by Obama, and replaced by the realist Panetta, who was replaced by the realist Chuck Hagel, who was replaced by the realist Ashton Carter. Dem Presidents always appoint realists to Sec Defense and sometimes Dem presidents will appoint republican realists like Gates and Hagel under Obama and republican realist Cohen under Clinton.
A GOP candidate for prez like JB has to court both the realists and the neocons, to try to convince both groups that they will have role in his foreign policy decision making. Bush may be courting James Baker today, but last month he was courting the prominent NeoCon Paul Wolfowitz.
If Jeb Bush is elected prez, he will likely appoint a neocon as Sec Def and a realist as SoS and NSA, because that is usually was GOP presidents do.
George Bush appointed Realist Colin Powell as SoS and Realist Condi Rice as NSA and gave the SoD job to neocon Rumsfeld.
GHW Bush gave the SoS to Realist Baker and NSA to realist Scowcroft and SoD to NeoCon Cheney.
These conflicts between the NeoCons and Realist have been going on since the neocons left the dem party in the 70s to become republicans, but the conflict has gotten worse in the post cold war period.
But if you look at the history, under Nixon, Ford, Carter, Reagan, and GHW Bush the Realists were the most influential foreign policy group. But under Clinton, the Liberal Interventionists rose to power and under GW Bush, the NeoCons rose to power. Under Obama, the realists have had the most influence.
Anyway, this article is published at a NeoCon website, the Free Beacon. And the NeoCons want Rubio in the presidency.
bttt