I haven't gotten very far on my PCO history project, only up through the 1940s with 2010 as a bookend. If I was to come up with a conclusion so far, I'd say compared to today, there have been decades of high participation in the PCO process, much higher than today. But, you can find years when our average now wasn't out of the ball park.
What I do find striking is the years when every single PCO slot had at least one candidate. Competitive races were somewhat rare (though sometimes as high as almost 70 percent), but the full ballot implied a desire on the parties' behalf to have as many PCOs as possible.
Anyway, seems like this year on the Republican side, the PCO races are of high interest across the Northwest again. Here are some links noting the PCO battles that are going on between Ron Paul supporters and long time Republicans.
Ridenbaugh Press: The Precinct Wars.
In Twin Falls County, the Republican Liberty Caucus ran a slew of challenges to often-veteran precinct officers, and won almost a third of the seats. The mainstream party leaders expressed relief that the challengers hadn’t won a majority, but they’d better not count on the fermet to ease off soon. Many races were competitive; one was decided by a coin flip.Spin Control: County awash in PCO candidates
In theory, Democrats and Republicans should each elect a PCO for each of Spokane County’s 314 precincts every two years, although in many years the parties often go begging for willing candidates, and when they find one, there’s no contest for the job.
Not this year. In 105 precincts, about a third of the county’s total, there will be contested elections. Almost all, 101 races, will be for Republican positions. In one precinct, a South Hill precinct near Roosevelt Elementary School, both parties have contested PCO races with two Democrats and three Republicans.Clark County Politics: My Mistake: a FOUR way race in the 620 precinct.