Biden is up around the same as polls had Dems in 2018,and the polls were lower than the actual results June/July 2018 polls (Dems won by 10 million votes and 23 out of 33 Senate races 4 months later)
I find voting trends in politics fascinating. I really do, you get Obama elected then in two short years you get Congress Republican sweep then you re elect obama then you elect Trump and then you get another Democratic boom in Congress it's all so crazy and so interesting. I know there's a method to the madness.
Sadly Dems only go out to vote in high numbers when they really like a candidate (Obama) or really hate a Candidate (Bush /Trump)
But bush was re elected, if only it where that simple. Any nobody really liked bush, most thought he was an idiot, which he basically was.