Complex sentence: Governor Larry Hogan, who opposed the project while campaigning in 2014, approved the Purple Line in June 2015, but cancelled its sister project, the Baltimore Red Line, citing excessive costs.
Split into simpler sentences: Governor Larry Hogan opposed the Purple Line project while campaigning in 2014 but approved it in June 2015. At the same time, Hogan cancelled its sister project, the Baltimore Red Line, citing excessive costs.