Trump enhanced their cause. It couldn’t have survived and thrived without being constantly fed by Trump. He made the best case against himself anyone could ever have made, which is what Biden’s apparent victory demonstrates. That, and the fact that, with the exception of Cory Gardner in Colorado, elected Senate Republicans thought to be doomed or nearly doomed all survived—Susan Collins, Thom Tillis, Joni Ernst, Lindsey Graham, Steve Daines, and probably Alaska’s Dan Sullivan. (Martha McSally and Kelly Loeffler were both appointed to their seats.)
The fact that Washington Republicans weren’t ditched, combined with Biden’s colorlessness and lack of an agenda, means that the astonishing turnout among Democrats and independents was driven by one overwhelming objective: To drive Donald Trump from office. And that, it seems, is the only clear message of the 2020 election.