Jacob Heilbrunn reacts to the end of the “three amigos” of McCain, Graham, and Lieberman with the retirement of the latter:

But are McCain and Graham about to suffer a loss of prestige? According to the Times, what is at stake may be as much about GOP foreign policy as it is about bipartisanship. At a moment when the GOP has become increasingly isolated as President Obama pursues a more cautious course abroad–no intervention in Syria, withdrawal from Afghanistan–Lieberman’s retirement could pull out a vital neoconservative strut

I think all of this gives Lieberman too much credit or blame for the malign influence that McCain and Graham have on the foreign policy debate. McCain wasn’t lavished with media attention in the past because he worked alongside Lieberman. He and Graham continue to be taken far too seriously on foreign policy even when they aren’t teaming up with Lieberman on a particular issue. McCain has long been a media favorite, and even when journalists no longer like McCain they can’t stop paying attention to him. He was treated with great deference on foreign policy questions before the formation of the familiar trio. On many major foreign policy issues, Lieberman has been in a sort of exile from his former party for years since he lost his primary race in 2006 and ran as an independent. He doesn’t really provide McCain and Graham with political cover or a “veneer of bipartisanship.” It’s more that they have taken him in after he was disowned by a large number of Democrats.

We should also bear in mind that there are other new members of the Senate that have been encouraged to act as Lieberman replacements now that he is departing. On Benghazi-related matters, it appears that Sen. Ayotte is filling the void for the moment, but on other issues Marco Rubio is the most obvious and likely candidate to take Lieberman’s place as a regular ally of the other two interventionists. It would be good news indeed if Lieberman’s departure from the Senate had additional positive effects on the quality of Republican foreign policy thinking, but there seem to be only too many new Republican Senators eager to pick up where he left off.