WASHINGTON — A sharply divided House approved a Republican plan Wednesday to launch a campaign-season lawsuit against President Barack Obama, accusing him of exceeding the bounds of his constitutional authority. Obama and other Democrats derided the effort as a stunt aimed at tossing political red meat to conservative voters. Just a day before lawmakers were to begin a five-week summer recess, debate over the proposed lawsuit underscored the harshly partisan tone that has dominated the current Congress almost …