Primary season has long been called the silly season; and the tail-end of the silly season is generally understood to be the savage season. And then comes the semaphore season: the moment when candidates and near-candidates begin signalling to the stronger runners that they’d be willing to fall into step as Vice President.

These signals are necessarily subtle.

No one still on the ballot can shake the sense that events might yet catapult them to front-runner status. And those off the ballot generally want to seem attractively modest about their willingness.

But two pieces today caught our eye along these lines. First, John Edwards made the argument recently that while he has more profound differences with Hillary Clinton, on Iraq and other issues, he’s not all that far from Obama.

“The differences between Sen. Clinton (D-N.Y.) and myself are much more dramatic than the differences between Sen. Obama and myself.”

Is that more than a hint? Not much. Still, for a candidate campaigning against Obama, and one who needs to move past him to have a shot at the Presidency, the hint seems broader than might otherwise appear.

And let’s not forget that Edwards has successfully negotiated this dance once before.

The second signal? Chuck Hagel, the Vietnam Vet who now understands — having seen Ron Paul ride an anti-war stance to sudden fame and campaign riches — that he may well have missed his best chance at the White House.

Asked yesterday whether he’d consider running second on a Democratic ticket, the Republican Senator called Hillary Clinton “capable,” and went on at some length about how he’d give it serious consideration.

We’ve said all along that if Hillary wins the nomination, she will almost certainly double-down on machismo: she will pick a General, or a decorated war-vet, no doubt one with solid Red-state credentials.

Jim Webb would be the proto-type, but Hagel might just fit into a suddenly Right-veering Clinton campaign headed for the general election.

Curiouser and curiouser, as Alice used to say.

Late Update, Friday, 1:35 pm:

VDB-reader Chris writes in to suggest that we’ve missed the boat entirely: that Edwards is actually looking to be the second choice for Obama voters under Iowa’s recondite caucus system, rather than looking squarely at the VP slot.

A point very well-taken. But who’s to say the man’s not actively engaged in both? The two goals aren’t mutually exclusive. And those two goals may be only a fraction of the number Edwards currently has scrolling through his mind.

He’s nothing if not nimble, we’ll say that.