This is what happens in a "wave" election.
I don't think it was that impressive a showing for the D-trip. Wilson and Shays would have been felled if it had been a "wave.' I agree with Amy Walter that it was more like a tornado. The GOP got flattened in Iowa, Pennsylvania (except Jim "Goner" Gerlach) and New Hampshire. They survived in Ohio largely unscathed despite massive scandal problems.
Ohio had to do with the inner strength of the Republican party machine there. They are still not to be underestimated, even after this brutal year.
Wilson and Shays are fighters to the core, just ruthless campaigners. Those type of people are very hard to beat. It helped Wilson that she had a crappy opponent, but the statewide mood in New Mexico was about as bad for the GOP as it's ever going to get. Shays probably benefitted from the up-ticket candidates. If Weichert survives, it'll be because of the crappiness of his opponent also. He's a tough campaigner too.
I too am convinced that Gerlach's opponent was not top-notch either.
Castle and Dent had no opponents. Kirk didn't win by very much this year.
We'll see what happens to Simmons; that CD has a long history of close elections and switching parties.