There are two pieces here:
1). It is easy now that Trump’s polling has begun it’s long descent off the cliff to begin the late-in-the-game second guessing and general abandonment of Trump by people who either are trying to get elected in blue, light-blue or pink states or make their living from within GOP. The harder thing to have done, the thing that would have taken actual courage, was to have this conversation during the Primaries where it would have actually mattered. Some #NeverTrumpers tried and deserve the credit they are receiving for saying, correctly, that Trump would get crushed in a general election and would set the Republican brand back decades with non-white, non-male voters. Others though, who either played nice with Trump in the early stages of the campaign (like Ted Cruz and his team) or who are still denouncing specific things that Trump says, but not the candidate himself (like Speaker Ryan and Sen. McConnell) will have no place to turn to when the blame game starts in a few months time. Trump is clear, he is going to blame the GOP establishment. Who can Paul Ryan blame?
2). It has been said before but it bears repeating. Trump is the final phase of the disease that has plagued the GOP since they instituted the Southern Strategy. He is the clear result of the GOP’s metamorphosis into a regional, white, nationalist, protectionist, anti-intellectual and racialist party. So as much as I am inclined to feel sorry for the “sane” and “reasonable” conservatives left out there as they watch their party writhe and die, it is worth remembering that the party has been sick for 40 years with this disease and even if it’s final phase is particularly painful, it was never going to end any other way.