RICHMOND There was Democrat Mark Warner, all teeth, smiling grandly. And next to him stood Republican George Allen, ruddy-faced and grinning, too. Surrounded by reporters at the Richmond Marriott hotel last month, the pair might have been taken for best buddies as they celebrated the success of Virginia's tough school standards. Allen, Virginia's junior senator, slapped his arm around Warner's shoulders and sang the governor's praises: "We may be in different parties," he said as Warner nodded, "but it's great, actually, for Virginians to know there is that commonality there." Well, sure, but how deep does it go? Picture, now,...