WASHINGTON — A divided Senate confirmed Catherine E. Lhamon as the Education Department’s assistant secretary for civil rights on Wednesday after she faced intense criticism from Republicans, who questioned her views on transgender students’ rights and how schools should address sexual misconduct. The Senate voted 50 to 50 along party lines, with Vice President Kamala Harris casting the tiebreaking vote. Ms. Lhamon, who was confirmed unanimously to the same post under former President Barack Obama in 2013, carried out some of Mr. Obama’s most aggressive civil rights initiatives. During her tenure, the Education Department pursued a broad range of civil rights investigations into colleges and universities accused of mishandling complaints…