OF 435 seats in America's House of Representatives, perhaps 36 are considered neither decisively red or nor blue. Another, in the pork-and-peanut belt of southern Virginia, joined them earlier this year, when a federal court re-drew its boundaries to favour a Democrat. The district's long-time Republican incumbent, Randy Forbes, decided that rather than risk losing, he would simply move: to an open, neighbouring seat friendly to the GOP. Mr Forbes, the number 3 Republican on the House Armed Services Committee, has become a symbol of the down side of partisan redistricting, or gerrymandering. His hop from one district to another is being viewed with cynicism by an electorate that, as Donald Trump's victories suggest, is fed up with a party establishment that seems to look after itself.

Mr Forbes, who could face two others in June for the GOP nomination, may have fueled that wariness with another strange decision. He will not actually move to his new district, choosing, instead, to continue living in the old one—because he can. Efforts by some states to impose district-specific residency have failed. In 2000, a federal appeals court junked a California law requiring House candidates live in their districts, saying that the statute is inconsistent with the constitution.

For some, Mr Forbes's decision seems anachronistic. Following the Civil War, in the states of the defeated Confederacy—among them, Virginia— Northerners poured in, snapping up elective offices for personal financial gain. They were known as carpetbaggers, after the heavy, woven satchels they carried. Mr. Forbes is all but depicted as a modern-day carpetbagger in pointed editorials by his hometown newspaper.

Across America, it's something of a tradition for congressional candidates to move in pursuit of the best opportunities. In 2010 in Illinois, a Republican challenged a Democratic incumbent for the House even though the Republican lived in an adjacent district. By 2015, redistricting had candidates shifting districts along Florida's Gulf coast. And in a rural patch of New York State, a Democrat moved from the New York City suburbs to run for a soon-to-be-open Republican congressional seat.

Efforts to de-politicise redistricting have had limited success. According to the National Conference of State Legislators, 15 states look to independent panels to help draw congressional lines. About 25 rely on them to determine state legislative boundaries. These panels can only accomplish so much.

A ruling this week by the Supreme Court could further complicate the issue of redistricting. Deciding a Texas case, the court said that in drawing legislative boundaries, states must count all residents, regardless whether they are voters. That might compel state lawmakers to become even more artful in map-making, further bending lines to capture friendly precincts or to bypass hostile territory.

"The vast majority of incumbents are solid, predictable conservatives or liberals, with voting records to match," says Larry Sabato, a political scientist at the University of Virginia. "It is difficult and unpleasant and, maybe impossible, for them to adapt to a moderate competitive district. Just as Americans generally are seeking shelter in localities that reflect their own social mores and party choices, so, too, do member of Congress seek territory that reflects their own shade of red or blue."

The new Virginia district map was drawn in response to a ruling by a court panel that when drawing the current lines in 2012, state Republicans packed African American voters into one district, to create surrounding seats that were lopsidedly white and reflexively Republican (One of those seats was Mr Forbes's).

Since Mr Forbes announced he would leave his old district two other Virginia politicians have indicated they will follow his example, in the district he is quitting. A Republican local lawman and a Democratic state legislator, neither of whom currently live in the district, are standing for their party’s congressional nominations there.

Meanwhile, the state's congressional election is two months away. Mr Forbes has yet to fully introduce himself to voters in the new district. And it is not clear when a Republican appeal to the Supreme Court to suspend the new boundaries will be decided. The death of Justice Antonin Scalia, a critic of voting rights protections, could mean an unfavourable ruling for Republicans.