BOSTON — Gov.-elect Deval Patrick said Thursday he will rescind a new agreement between the state and federal authorities that allows State Police troopers to arrest illegal immigrants. Speaking with reporters after a lunch meeting with state legislators, the incoming governor said he believes the troopers have enough to do already without having to also enforce immigration laws. "If I have that power, I'm going to rescind that agreement," Patrick, a Democrat, told reporters. He added: "I do believe I have that power."