One reason that Democrats enjoy the Chuck Hagel nomination, and one reason he's more insulated from criticism than Susan Rice was, is that Hagel spent years as a reliable conservative Republican. The person who did the most frontal damage to Rice, John McCain, was a close and respectful ally of Hagel. It would be hard for McCain to flip now, if he even wants to, because the Hagel relationship is intertwined with McCain's biggest struggles and image-defining moments.
In 1998, intrigued by the rising star senator with the war record, George W. Bush and Karl Rove invited Hagel down to Austin. As the frontrunner, Bush was trying to lock up as much support from the establishment as he could, and pulling Hagel -- a natural McCain ally -- would have been a coup.
Karl Rove writes about the meeting in his memoirs.
We were trying to limit public discussion about a presidential bid, but some "friends wanted to be heard from, such as Nebraska Republican U.S. senator Chuck Hagel. He insisted on coming to Austin for what we agreed would be a private visit. But he immediately trumpeted the meeting to papers back home by endorsing Bush and saying, "There's only one person who is a giant among that crowd, and that's George Bush. I think George Bush is tougher than his dad... more conservative than his dad and more disciplined than his dad." Someone elevating the younger Bush by trashing the elder Bush just thrilled -- thrilled! -- the governor, who questioned my judgment in allowing Hagel anywhere near Austin during the gubernatorial campaign.
Sure enough, Hagel became a reliable McCain ally. During the South Carolina primary, he attacked Bush for letting a renegade "veterans' rights" activist unload on McCain during a speech introduction. He attacked the idea that McCain's independent streak made him a bad Republican, because McCain was "the one guy with Bob Dole [in 1996] as his campaign was going down the tubes." But after McCain lost, he agreed with his friend that there was a "new international sense in the electorate of who we are as a nation that has left the political parties behind." The previous experience with Bush was one reason Hagel's moment as a possible veep was illusory -- he was vetted, but even Hagel suspected it was for show, a way to prove to the media that Bush took seriously the stuff that the media took seriously. McCain stayed respectful to Hagel through 2006, when the New York Times profiled the possible 2008 outsider presidential candidate; McCain told Joe Lelyveld that he'd support Hagel for "any" job, up to Secretary of State.
No one in the Republican party has more clout criticizing Obama nominees than John McCain does. And his voice is largely absent from the Hagel conversation. Bill Kristol's filling the gap as best he can, but Hayes Brown reminds us that Kristol, too, was a Hagel fan in 2000, back when the senator stood for "being a veteran" and "criticizing the party's tactics."