Safe because of his understanding of the local lifestyle, AG, and that he did a big save earlier this year when a major water system that services a large chunk of the state went down. He made sure and emergency set up was in place and a new channel planned in a hurry. That system supplies a lot of farms and ranches, including Tester's farm... it's a large area that it services.
It's not so much that he saw his farm in danger but that he saw everyone in the service area were at risk during a very hot year in the middle of growing season. He came through and those affected will remember him for that, the veterans will remember him for bringing better services to them too. Montana has one of the highest per capita contributions to the armed services, we have a lot of veterans and the services have been pretty sparse until Tester started making things happen.
People are also getting tired of the charlatans like daines, gianforte, zinke and the wannabe, sheehy. It's an old tale of woe and it isn't making the locals feel safe. We have a lot of incoming population and old timers are seeing too much development on the landscape that is already threatening the ecosystem they all came here to enjoy. There have been several surveys about this and the general consensus is that there is too much tourism and trophy homeism and it's not a good thing, there is no affordable housing anywhere. Only those with lots of money can afford to rent or buy... anywhere in the state.
I think Tester is going to be safe in his Senate seat. If the magat squad have to parade their big guns out here to promote their lousy candidate, they're behind and running scared.
Magats, it turns out, aren't very good neighbors and the sane folk have had it, IMO.