Obviously the Presidential race will greatly reduce ticket splitting, but given that Rosendale lost this race in 2018 when turnout was higher than 2016, it's a very striking red flag for his chances.
Actually, 2018 turnout was lower than 2016:
| Year | Total Votes Cast | Total Registered Voters | Turnout Percentage |
| 2016 | 516901 | 694370 | 74.44% |
| 2018 | 509213 | 711844 | 71.53% |
Of course, turnout alone can't fully explain election results; Rosendale won in 2016 against a non-incumbent Democratic opponent but lost in 2018 against an incumbent Democratic opponent running for re-election before winning in 2020 against another non-incumbent Democratic opponent. (As I mentioned elsewhere, since 2014 the only Democrats who won statewide elections in MT were those who were running for reelection to their existing offices, and that applied to Bullock in 2016 and Tester in 2018; all other Democratic statewide candidates were running for positions they hadn't yet occupied and were all defeated by their respective Republican opponents.)
I was referring to the differential between 2016 Pres and 2018 Sen directly - roughly 7,000 more votes were cast in the latter race than the former. This is incredibly rare and not likely to be replicated, especially with both the Presidential and Senate race on the same ballot. Rosendale looks even weaker when you see that the same dynamic happened in the concurrent 2018 House race yet Gianforte still managed to win.
Entirely possible given the turnout figures you cite that this was due to an abnormally large number of voters blanking the Presidential race in 2016 (this looks likely given that the House race in 2016 saw more votes cast than the Presidential). This is another dynamic not likely to be replicated and if it is somehow, Tester will need the lion's share of Presidential nonvoters.
Poll
