v. To redraw electoral boundaries so that most or all of an incumbent's district becomes part of another district that has a popular incumbent from the same party, meaning the two must run against each other.
The goals of modern gerrymandering haven't changed much since Burton's day: Either "pack" voters hostile to the mapmaker into the fewest possible districts, or "crack" them into ineffectual minorities among districts that the mapmaker's party is sure to win. "Pair" unwanted incumbents in the same district so one has to go, or "kidnap" them by pulling them out of their existing districts.
—“The blood sport of redistricting,” Chicago Tribune, January 17, 2004
The oddly shaped Twelfth District in Pennsylvania is a good example of "kidnapping"— in effect, moving an incumbent's established constituency out from under him or her.
—Don Peck & Casey Caitlin, “Packing, cracking, and kidnapping: the science of gerrymandering,” The Atlantic Monthly, January 01, 2004
2003 (earliest)
Kidnapping places two incumbents from the same party in the same district.

Frank Mascara was kidnapped. A Democrat first elected to Congress in 1994, Mascara represented a district in the rugged industrial country south of Pittsburgh. … With the Republicans in charge in Harrisburg, Mascara knew he would be little more than a spectator to the redistricting process. "I still thought my district would for the most part remain intact," he said. "That didn't occur. When they drew the new lines, they started in Allegheny County, which is north of here, and made, like, a finger out of that district, and the finger went down the middle of the street where I live. The line came down to my house and stopped." The Republicans' meticulous line-drawing through Charleroi was designed to force Mascara into a primary battle with his fellow-Democrat John Murtha, which it did. Murtha defeated Mascara, ending his congressional career and reducing the Democratic presence in the House by one.
—Jeffrey Toobin, “The great election grab,” The New Yorker, December 08, 2003