FORMER HOUSE SPEAKERSPaul Ryan, John Boehner and Newt Gingrich plan a fundraising campaign to defend Republican-controlled legislatures in Texas, Pennsylvania and a handful of other states from an onslaught of Democratic money and attention. Control over the congressional redistricting process is at stake in 2020: The Republican State Leadership Committee cites estimates that as few as 42 state legislative races could determine as much as a 136-seat swing in the House over the next decade, based on how those legislatures draw new maps. The three leaders will form an advisory council for the RSLC.

“We...