As the damage of his criminal war on Iran escalates going into the midterms, and beyond, the instinct for self-preservation among trumpublicans could kick in.
Sooner or later, it is going to become clear to them that there is NO WAY OUT with the felon-in-chief in the WH. When/if that grim and inevitable reality dawns on enough of them, I wouldn't be surprised to hear leaks about visits to the WH by little delegations of from the hill. The content won't be leaked, but you can bet they'll be pitching face-saving resignation for health reasons or some such bullshit. Particularly if we win the House (and perhaps Senate) and put the full extent of the corruption and crimes front and center in the public's mind. There are only so many of them who will be willing to sacrifice careers to go down with the rotting corpse of trump around their necks.
Right now they are hanging on to the fantasy that the criminal war on Iran will magically end and things will go back to some survivable trumpian business as usual. When it is clear that there is NO WAY OUT with him in the WH, things could shift dramatically.