The results are subtle enough that they don't jump out in a casual look. But someone who knows stats at the site Interstices has worked it out: A strong relationship between support for the former Republican presidential candidate Ron Paul, and for Idaho state Senator Shirley McKague.
From Interstices: "The raw votes by precinct correlate more closely than the percent of vote. And given that total votes cast in each race were very close (about 120 more votes in the Legislative race than the Presidential Primary, which is counterintuitive), it seems fair to compare the raw vote totals head to head as in the above scatterplot. . . . Using that r-square can mean — in effect, without a big stretch — that three of every four Ron Paul voters also supported McKague." (Visit their site for the charts.)
This feels implicitly about right. And without running the stats in a detailed way, you can see it generally in a review of the 14 precincts in legislative district 20, where McKague (appointed to the Senate in the last term, but a long-time House member) was challenged by Representative Mark Snodgrass. McKague is a hard-core anti-government ideologue, formerly of the John Birch Society; Snodgrass would be considered conservative by conventional Idaho definitions, but also amenable to working on such things as air quality and transportation and education needs.
Of the 14 precincts, Snodgrass won two (43 and 48) and tied in a third (135); John McCain beat Paul by about 3-1 in all three, somewhat better than he did in most of the district. The margins varied enough that a detailed statistical analysis was about the only way to tease out a clear connection.
Interstices: "There may be a chicken and egg question going on here, whether the Ron Paul vote can first and then the voters continued to work down the ballot and voted in the Legislative races, or was it the Legislative race that brought out voters and they happened to have a Ron Paul affinity, or perhaps do not care for McCain?" We'd suggest the answer is simpler: The voters who were there for one simply found elements to support in the other, not that one is responsible for the other.
And we're tempted by this thought too: That, given the myriad differences between a Paul and a McKague, what you're really seeing here is a reaction against "mainstream" Republicans at this point - be those like McCain or like centrist Idaho conservatives.
(Hat Tip to Kevin Reichert at the Idaho Statesman, who also posted on this.)