This chart is from the latest CBS News / YouGov Poll -- done between August 10th and 16th of 4,989 respondents in the 57 most competitive congressional districts, with a margin of error of only 1.8 points. Those districts are:
AR02, AZ01, AZ02, CA10, CA21, CA25, CA39, CA45, CA48, CA49, CO06, FL18, FL26, FL27, GA06, IA01, IA03, IL06, IL12, KS02, KS03, KY06, ME02, MI08, MI11, MN01, MN02, MN03, MN08, NC09, NC13, NE02, NH01, NJ02, NJ03, NJ07, NJ11, NV03, NY19, NY22, NY24, OH01, OH12, PA01, PA05, PA06, PA07, PA17, TX07, TX23, TX32, UT04, VA02, VA07, VA10, WA08, WV03.
The survey shows Democrats with a 3 point overall edge in those 57 districts. This is very bad news for Republicans, since 52 of those districts were Republican seats and 5 were Democratic seats. All the Democrats have to do is win half of the 52 Republican seats and they will gain control of the House of Representatives.
If Democrats don't take this for granted, and turn out to vote in large numbers on election day, that can be done. One big things in their favor is the gender vote. While men support Republicans by an 8 point margin, women support Democrats by a 12 point margin -- and women tend to vote in larger numbers than men do.