Artillery spotting for Obama

If McCain wants to play guilt by association, he's what you might call a target-rich environment.

If Obama has to respond in kind, WSJ/CBS poll numbers cited by the WSJ's Gerald Seib suggest where to concentrate fire:

Add the fact that the new Journal/NBC News poll shows that more voters are bothered by former lobbyists working for Sen. McCain's campaign than are troubled by Mr. Wright's ties to Sen. Obama, and the risks of a down-and-dirty campaign become clear.

Clear as mud.