McCain's chief in-house blogger Michael Goldfarb told bloggers on a morning conference call the after hours texts were a "juvenile, in your face jab at Hillary Clinton."
Goldfarb also said Obama's decision to choose Biden was "from a position of weakness" and "it's almost a relief Obama didn't pick Hillary because she's quite a formidable candidate."
Update: Carl Cameron, via GretaWire, reports disgruntled Clintonistas are upset with the 3am symbolism as well. "Campaign Carl" writes, "resentful Clinton backers are now aggressively speculating that the Obama campaign delivered the text message at 3am ish this morning as a payback to Clinton for the “3AM” attack ads raising doubts about Obama’s experience to handle a crisis call at the White House in the dark of night."
Update 2: Goldfarb follows up with a blog post. "By all accounts, Hillary Clinton was not vetted for the second spot, nor was she consulted by the Obama campaign on who should be taken--not even as a courtesy," Goldfarb blogs. "If she had been the pick, the 3 a.m. text message might have had some real resonance--a signal that the two had put a tough campaign behind them in order to work together on the serious issues the next administration will have to deal with. But what's with holding the text message until 3 a.m. for Joe Biden? The only explanation that makes any sense is that Team Obama just couldn't resist one last dig at Hillary."