Zinke has held this for 20 years & didn't fall even in the anti-Bush & Obama wave years of 2006 & 2008. If this would fall, it would be beyond a landslide for House Republicans. Republicans hold close to 25 seats in NY & CA alone. Democrats have never needed the Montana House to win a landslide election.
Trump won by 21%, Gianforte by 6%. A 15% Swing is pretty big. And Ryan Zinke won by 15%. If you have a 9% swing everywhere from 2016 House results , then Republicans are facing a landslide loss !
In 1996, Rick Hill (R) knocked off incumbent Pat Williams (D).
During the big 2006 and 2008 Blue waves and the 2010 Red wave, Denny Rehberg (R) was the one representing MT-AL. Rehberg was in there from 2001-2013.
Current Senator Steve Daines (R) was in this seat for one term from 2013-2015.
Then, Ryan Zinke (R) won in 2014 and took over from 2015-April 2017.