The other thing - as oft mentioned - is that Democrats tend to sink in the polls much more easily than Republicans do. Look at Biden, right now his approval ratings aren’t much higher than Trump’s, even though the guy hasn’t uttered 13,000 lies, killed half a million Americans, etc. They need to do a much better job to stay afloat and are not - at least not in a way that the media can’t poke holes at them (for instance, have a strong economy without inflation.)