Complex sentence: The Republican-controlled state legislature dismantled Altmire's district, and most of its territory was merged with the neighboring 12th Districti, represented by fellow Democratic congressman Mark Critz, who defeated Altmire 51% to 49% in the primary election.
Split into simpler sentences: The Republican-controlled state legislature dismantled Altmire's district, and most of its territory was merged with the neighboring 12th Districti, represented by fellow Democratic congressman Mark Critz. Critz defeated Altmire 51% to 49% in the primary election.