I have found an interest in national politics to be ubiquitous in the Far West (I'm not sure what exactly you mean by "Old West" since that could refer to a variety of things). I was a co-editor of the Gold-Rush-era letters of brothers Ethan and Hosea Grosh (1849-1857). They often wrote home to Philadelphia about their intense interest in national politics - following the events in Missouri and Kansas and canvasing for the new Republican Party in California during the 1856 campaign. In that year, they visited the Western Great Basin, but they hurried back for the election so they could do what they could for their party. They had numerous references to the national political turmoil of the 1850s.

I am also finishing a five-year project of editing and annotating the Journals of Alfred Doten (1849-1903). He was a '49er who became a California farmer, who then went to the Nevada Territory to mine once again, and then he became a journalist. From the start, his journals are fixated on the National political scene. I have written nearly 400k words of annotations for the more than 1.6 million words in the journals, and a significant number of those notes deal with national politics - even before he became a journalist in the early 1860s. Like the Grosh brothers, Doten was a Republican, and together, their observations about how local political issues fit into the national scene are full of insights.

These are only two sources - with which I have been particularly involved - and they are only a small slice of the pie - one finds similar echoes in many primary sources.