According to Chris Cillizza, a Washington Post/ABC poll shows the Democratic candidate way ahead of the Republican candidate.
Asked if the election were held today which party's candidate would they vote for in their own congressional district, 53 percent of registered voters said they would back the Democratic candidate, compared with just 38 percent said they would support the Republican candidate... Democrats have now led in the generic congressional ballot in a Post-ABC survey for the better part of five-and-a-half years.
As Cillizza writes in a state-by-state analysis, "the national playing field will be heavily tilted toward Democrats."