Barack Obama's vice presidential search team had begun floating the name of former Secretary of Agriculture Ann Veneman, one of George Bush's most loyal lieutenants, as a possible running-mate on the 2008 Democratic ticket.

What the Obama camp is doing is clear enough. They are signaling that the candidate might consider a bipartisan "unity" ticket. That's reasonable, as long as the Republican has some record of taking stands that might by some reasonable stretch of the imagination be considered breaks with Republican orthodoxy.

Of course, Nebraska Senator Chuck Hagel, an edgier critic of the Bush administration's foreign policies than most Democrats who recently traveled with Obama to Afghanistan and Iraq, tops most lists of cross-over contenders.

Someone like former Rhode Island Senator Lincoln Chafee, a steadfast Iraq War foe who has endorsed Obama, could find a place on a list of possible running mates.