On Monday, Gov. Eric Holcomb signed GOP legislators' redistricting proposals into law, making Indiana the fourth state to complete a new congressional map. The plan strengthens the GOP's 7R-2D domination in the state, dramatically shoring up GOP Rep. Victoria Spartz (IN-05) in the Indianapolis suburbs. But Democrats are breathing a sigh of relief: had Republicans targeted freshman Democratic Rep. Frank Mrvan (IN-01), it could have been 8R-1D.

By far the biggest change is in the suburban Indianapolis 5th CD, one of the few blue-trending parts of Indiana. As expected, Republicans stuffed northern Marion County — which Spartz lost by 29 points last year while winning by four points district-wide — into Rep. Andre Carson's safe blue 7th CD. As a result, the 5th CD zooms right from Trump +2 to Trump +16 — exhibit A of how partisan mapmakers can eliminate purple seats from the battlefield.

But Indiana is also a good example of why parties don't always pursue maximally aggressive gerrymanders. Republicans could have converted Mrvan's blue-collar Gary/Hammond 1st CD, which voted for Barack Obama by 24 points in

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