According to this CNBC poll[1], on the question of "party preference to control Congress", the Republicans come out ahead. Its close, but hardly the landslide Democrat victory you would expect if nobody supports the GOP.
I would recommend you take another look at the polling data[2]. It might help pop some bubbles.
It's the generic congressional vote, which is simply the percent of people polled who prefer either party. It's analogous to the popular vote for President, not the percent of seats either party is predicted to win.
All the surveys are only of "likely voters". People who live in heavily gerrymandered districts tend to say "I'm not planning on voting". Also a lot of younger people who generally support Democrats aren't even included in the surveys.
If this were generally true, you'd see more polls erring in favor of Republicans. I can't recall any mainstream polling misses that have; do you have any references?
That doesn’t help when you ask if someone is a likely voter and they say no because of who’s running.
Granted it doesn’t say it’s asking likely voters, but somehow they got 95% of responses say they are registered voters when only 50% of Americans are registered voters.
There are many possibilities, but the point stands that it’s clearly a very biased sample. Almost 80% of people between 65-74 are registered voters but that’s still a long way from 95%.
In raw numbers, far more people support the Democrats than the Republicans.