Gov. Rauner Losing Another Republican Ally In Springfield

(CBS) -- Republicans in Springfield are about to take another big hit.

State Sen. Matt Murphy of Palatine plans to resign Friday – this, after another high-ranking GOP leader quit last month.

Sources tell CBS 2 Murphy, a legislative leader, is set to become a political lobbyist.

Murphy was elected in 2006 and has been a supporter of Republican Gov. Bruce Rauner's "Turnaround Agenda," which was rejected by Democrats who control the Illinois General Assembly.

It's unclear why Murphy is leaving public service or who will replace him. He is the second high-profile Republican to step down in less three weeks.

Last month, Ron Sandack unexpectedly resigned from the Illinois House.