The media environment was much more localised in those days so there was less domination of national ideological issues. Many conservative voters in these small states would have been reading in the local paper how their Senator may be on the liberal side but was a Nice Guy FF who was respected in the Senate, had seniority and these committee chairs, which he had used to bring this industry to the state, and he'd stood up to the President of his party on this issue etc.. This is an interesting paragraph I just stumbled across:
[Church] was also careful to cater to his conservative constituency on issues like gun control, and voters respected his integrity and his independent stance against the Johnson administration, which was very unpopular by 1968. After a meeting in New Meadows, for example, a cattleman assured Bethine Church that she “needn’t worry. I’ll be for your man—but I’ll be damned if I’ll be for L.B.J.” That election year, the conservative Idaho Statesman broke precedent and backed Church, arguing that “no Senator from Idaho since [William] Borah has commanded so much respect in the Senate or the nation.” Even in conservative, Republican Payette, Idaho, one publisher confessed that there was “a lot of sentiment that he’s the best senator we’ve had in years.”
Voters were local-minded and cared relatively more about Idaho having a respected local champion than certain votes on national legislation, and didn't tend to associate local politicians with the national parties or incumbent president so much. Again because most of their information about their Senator came from local media, which increased the power of retail politics and helped incumbents.
In 1964, Joe Manchin could probably say "yeah I voted for Biden's Inflation Reduction Act, but as chair of the Senate Energy Committee I stood up to the President and brought the Mountain Valley Pipeline to West Virginia which produced x thousand jobs", and people would read about his vote in the Charleston Gazette with a glowing writeup from a Moderate Hero local journalist who knew his staff personally and liked the guy. In 2024 Manchin just gets bashed over the head by Fox News and Republican attack ads telling West Virginians how Manchin voted with Biden 90% of the time or whatever.
