Heller is treading in dangerous water right now. If I were Heller, I would run like hell away from Trump so I lose narrowly. Nevada will trend against Trump hard and Heller is target number 1. When he loses narrowly he can make a comeback for Governor perhaps or maybe running for the Senate again.
I agree that I think Nevada, along with California and Arizona, will probably be ground zero for anti-Trump/Republican sentiments in 2018 and Heller is on very thin ice, and also with MT Treasurer that the national mood might be able to carry some B-tier state legislator candidate across the finish line. But a good candidate would make things easier.