WASHINGTON — Sen. Robert C. Byrd (D-W.Va.), promoting his lifelong passion for the U.S. Constitution, has inserted into a massive federal spending bill a requirement that schools devote at least part of a day each year to teaching about the document. The provision would apply to all schools, elementary through college, that receive federal aid. Education groups worry that the provision could be the opening wedge in a campaign by Washington to influence what schools teach. Byrd carries a copy of the Constitution in his breast pocket — over his heart — and often waves it on the Senate floor....