I think 2006 is the only election cycle in this century where only one party flipped seats in the House (the Democrats). It's very rare. Even in 2010, Democrats flipped at least one (although it was one that was very blue anyway).
edit:
2008: Republicans flipped FL 16 (Tom Rooney), KS 2 (Lynn Jenkins), LA 2 (Joseph Cao), LA 6 (Bill Cassidy), TX 22 (Pete Olson).
2010: Democrats flipped DE (John Carney), HI 1 (Colleen Hanabusa), LA 2 (Cedric Richmond)
2014: Democrats flipped CA 31 (Pete Aguilar), FL 2 (Gwen Graham), NE 2 (Brad Ashford)
2018: Republicans flipped MN 1 (Jim Hagedorn), and MN 8 (Pete Stauber)
Most of these were due to re-alignment catching up (DE-AL, LA-06, HI-01, CA-31, MN-08, TX-22) or flipping back flukish wins from the previous cycle (LA-02).
In this case, re-alignment has pretty much caught up on a national scale where we don't have Dems holding Trump + 20 seats or vise-versa, and there were no crazy LA-02 level flukes in 2022 - yes seats like WA-03 was an upset but that's still only a Trump + 4 seat where MGP doesn't need that much crossover support to win again.
And some of those (LA-02, HI-01) were flukes because they were special election victories that would've been unlikely in the general.
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