As it faces the perennial task of convincing legislators from elsewhere in Maryland that Montgomery County’s streets are not paved with gold, the MoCo delegation in Annapolis is dealing with the latest in a continuing erosion of its seniority in recent years. The most widely bemoaned departure of late is Sen. Richard Madaleno of Kensington, whose budgetary expertise was a potent weapon in the delegation’s arsenal. He gave up his seat in an unsuccessful gubernatorial bid. Among other notable exits due to retirement or the pursuit of another office: Del. Bill Frick of Bethesda, the House of Delegates’ majority leader in 2017-2018; Del. Charles Barkley of Germantown, who chaired the subcommittee with liquor law jurisdiction; and Del. Sheila Hixson of Silver Spring, the second-most senior member of the House and a longtime committee chair. Two remaining veterans, Sen. Nancy King of Montgomery Village and Del. Kathleen Dumais of Rockville, will help fill the void; Dumais becomes majority leader, and King takes over the Budget and Taxation Committee. King joins two other senior legislators, Dels. Kumar Barve of Rockville and Anne Kaiser of Silver Spring, in chairing powerful panels. But almost one-third of the incoming Montgomery delegation will consist of freshman lawmakers, and the county’s legislative fortunes will turn in large part on how quickly they can acquire clout.