Why are polls skewed in favor of Democrats?

I was just researching why the national polls are consistently skewed towards Democrats. Part of the problem is who is willing to answer the phone from a strange number, and then respond to a pollster. Maybe Republicans are more likely to be busy working. But really, it’s not a record of who answered what in a poll, because the result has to pass through the pollsters’ “mathematical models” of demographics. Almost all the polls are done by Leftists filled with assumptions and preconceptions about the “likely voter”.  They never consider that the registered voter database is filled with fake voters, or unlikely voters who ended up in there because of a Democrat get-out-the-vote campaign ( to ballottraffick ). They have decided that there are about equal numbers of Democrats & Republicans while ignoring the larger portion of “independent voters” ( did not register with a party).

So that portion of “likely voters” registered Democrat is ~30%, but between a large fraction of Democrats who are voting Trump AND the canvassing results showing about 25% of registered voters are fake, the real voters for Biden will be below 25%. That is an awful lot of fake ballots they are going to have to create if they want to steal this next election.