They fought the good fight, and they are bitter right now about Trump being the nominee, but the majority of the conservatives will eventually fall into line and support the nominee. They have no other choice, this is a watershed election for conservatives, it is their line in the sand.
This election is about control of the Supreme Court for the next 25 to 30 years. There could be as many as 4 appointments to the Supreme Court over the next President's term of office. If the Democrats win in November and they follow Obama's lead and appoint younger progressives, we will have a liberal court for a generation. Under a Clinton presidency we will continue to see an attack on family values, religious freedoms and individual liberties will be curtailed and there will be an attempt to repeal the Second Amendment.
Conservatives may not find Trump conservative enough for them, but they can't sit this election out. If they lose in November, their way of live is finished.