The potential saving grace for Democrats is the relationship between midterm voting patterns and approval of the president has only increased over time. Since 2006, the president's party has won at least 86% of those voters who approve of the job the president is doing. They have never lost more than 90% of voters who disapprove of the president's job during the same period. The bottom line is that if you approve of the president, you're very likely to vote for his party, and if you disapprove, you're very likely to vote for the opposition in this polarized era. In 2018, Republican House candidates won 88% of those who approved of Donald Trump's job performance and lost 90% who disapproved. Republicans lost the House because more voters disapproved of Trump (54%) than approved (45%). Biden, at this point, is inverse of this with an approval rating in the mid 50s and a disapproval rating in the low 40s.