KEY POINTS FROM THIS ARTICLE -- A congressional forecasting model using political and economic fundamentals suggests that Republicans are favored to flip both the House and the Senate. -- A modified version of the model that also incorporates expert analysis also suggests that Republicans are favored in both chambers, but...

We build here on our “Structure-X model,” successfully applied in 2014. We first generate a 2018 forecast from our classic structural model. Next, we adjust this forecast on the basis of expert judgments provided in Inside Elections with Nathan L. Gonzales. With respect to the first step, the structural model,...