"Basically a tie" in what would normally be a safe R seat is ok to them?
The interesting thing is, lying to themselves doesn't put an end to the electoral bloodbath waiting later this year. At best, it's just their public face and they understand the implications privately. At worst, they are actively deluding themselves, thus potentially hindering their ability to do things that could help blunt the impact of a backlash in November.
Personally, I don't think there is much they can do at this point, but if there was anything, stuffing Trump away in the west wing, taking his phone away and basically making him a ghost would probably help somewhat. Most of the GOP's problems right now are of Trump's own making. The man is a walking scandal. If it isn't something from his past, it's something new coming from his mouth and/or twitter account.
^This
Trump's need to constantly view himself as popular handicaps the ability of Republicans to actually engage in course correction. Trump will refuse to believe that the party's problem's stem from his actions.
Yup.
Looking through how Lamb did in the part that will be part of the new PA-17, baring now major changes, I don't see how he doesn't win in November. I think you could logically rate that district as Lean D.