Every ten years, redistricting reshuffles the electoral landscape and, awkwardly, forces several incumbents to run against each other to keep their jobs. This cycle is no exception: there are six such "mashups" so far, and another is possible if a court-ordered map dramatically upends the lines in Ohio, which must shed one seat. In a sign of the times, all are primaries. Unlike past decades, there's not a single competitive general election faceoff so far.

Typically, already representing more of the "new" seat than your opponent is a big advantage in these situations. But this cycle, geography is taking a backseat to other factors: all three GOP primaries pit a more MAGA-oriented member with Donald Trump's endorsement against a Trump skeptic with more seniority. And ethics issues, racial voting dynamics and positions on Israel could dictate Democratic primaries in Illinois, Georgia and Michigan.

The first showdown is set to take place on May 10 between GOP Reps. David McKinley and Alex Mooney in West Virginia's 2nd CD. Two weeks later on May 24, Democratic Reps. Carolyn Bourdeaux and Lucy McBath

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