Your statement is absolute nonsense, and anyone who believes a similar down-ballot disaster would have occurred with Castle at the top of the ticket is deluding himself.
Our organization raised money for three GOP Delaware House challengers in districts that were strongly Republican or swing districts — both upstate and downstate. All three challengers LOST. Each of the GOP challengers credited their loss to COD specifically; and each challenger wanted Castle at the top of the ticket.
Ditto Colin Bonini. With Castle at the top of the ticket, he would have been elected State Treasurer.
Castle would have walked into Biden’s Senate seat just as Hoeven won in ND and Ayotte in NH.
Sorry to disillusion you, but the exit polls say otherwise; Castle would have lost just as bad. The huge and successful RAT voter registration drive negated any advantage that GOP candidates may have had. For THAT you can blame Tom Ross and his failure to register voters (3K in 4 years vs 60K) and his big mouth splintering the Party.
While we might like it; facts are real, feelings are not. BTW, while the GOP was busy bad-mouthing Christine O’Donnell at every turn; they never passed up a chance to horn in on her popularity when they had the chance.