Robert Novak retired from his regular column recently because of a brain tumor. But now we find out that he'll still pen the occasional piece, and the first one came out Wednesday. It's a shot across the bow of John McCain's campaign, a stern warning of doom ahead if McCain picks Connecticut Sen. Joe Lieberman as his running mate.

"Influential McCain backers, plus McCain himself, would pick the pro-choice liberal from Connecticut if they thought they could get away with it," Novak writes, continuing:

But they can't get away with it -- and this has been made clear to McCain by none other than Joe Lieberman himself.

Lieberman ... has close Republican friends. One of them prevailed on Lieberman to tell McCain that a McCain-Lieberman ticket would be a disaster for all concerned, and especially for the GOP. Lieberman's Republican friend told him that the Republicans would leave Minnesota in a state of disarray with a McCain-Lieberman ticket, alienating social conservatives who now make up the core of Republican voters ... The Republican operative who urged Lieberman to dissuade McCain from picking him believes that there is still a very useful role for the maverick Democrat in this campaign: as McCain's secretary of state.