it wasnt about the republicans being good, its just a historical trend
clinton got crushed, obama got crushed, trump got crushed. bush would have, without unprecedented 9/11 momentum. it was a safe bet that gas prices and inflation would AT LEAST keep an established trend going for biden
until we found out that trump is literally THAT bad
another factor i saw someone breakdown though, i guess gerrymandering is so bad at this point that theres only like 35 competitive seats left in the country. so the days of the House blowout might just be over entirely