[Meet the New Boss]

The Donor Class is putting pressure on every GOP politician they can reach.

The message is: damage Trump now so that Hillary “Western Hemisphere open borders” Clinton can win. Or you won’t see another dime from the Donor Class in the future.

[mrsmith]

Yep.
All these guys are on the wrong side of the donor/voter war.
And always have been.

[Alberta's Child]

There's only one problem with your scenario:

If their intention is to damage Trump so that Clinton can win, that would mean they must think he's going to win as things stand now. I'm not sure they would be that certain of it.