TALLAHASSEE -- U.S. Rep. Allen Boyd, a North Florida Democrat, is organizing a campaign for the U.S. Senate on the premise that he is well-positioned to win a crowded party primary and then challenge any Republican statewide. Boyd has commissioned a poll that portrays a wide-open contest among Democrats who hope to replace U.S. Sen. Bob Graham, D-Fla., next year, and he has started lining up supporters before a campaign announcement. "Sometime after July 4, he will probably make an announcement," said Barney Bishop, a Tallahassee lobbyist, political consultant and Boyd friend. Boyd, a congressman from tiny Monticello since 1996,...