In August Real Clear Politics had Democrats as having a 1.4 average lead on the generic ballot. One the latest Pew poll is factored in, Republicans will have led by an average of 3.8 points in five September polls. That's a 5.2 point shift. The Fix says it's due to an RV to LV switch.
Logic tells us that if Republicans are doing 5 points better in September than August that Republicans everywhere, on average, should be gaining 5 points everywhere. They're not in the senate. A few are doing a little better, but some are doing worse. Even candidates who people think are doing better really aren't. Mitch McConnell's lead now is the same as August.
1. It's possible the senate polls haven't caught up with the national situation. Most of them were taken before the recent switch or might still be using registered voters.
2. The state pollsters are getting it wrong. That seems unlikely. They all can't be getting the electorate wrong.
3. There won't be Republican gains in the polls. Even if Republicans gain 5 points on the generic ballot in Michigan that doesn't mean that they'll gain 5 in the senate race. As we saw in 2012, Democratic senate candidates can beat the House and Presidential vote, sometimes dramatically. Montana senator Jon Tester was winning those voters whether they voted Romney or Obama. House races are more reflective of the national mood because there are 435 to average out. Senate races are about the candidates. That's not to say that a more Republican electorate won't help Terry Lynn Land in Michigan. She just might not match the margins Republicans are winning the House seats by. I'd rather be the Republicans on the generic ballot right now, but it might not help the GOP in senate races.