Does anyone really believe an incumbent politician who complains that they'd love to participate in that debate but gosh darn it, their schedule just isn't going to allow it?
Barring a demonstrable emergency - which is a little difficult to demonstrate weeks or months out - such an excuse doesn't even reach the "my dog ate my homework" threshold. It didn't work when Oregon Governor Ted Kulongoski (or rather his staff) said he was just too busy to debate his Democratic primary opponents - a situation that changed, with the governor added to two primary debates, after a raft of bad publicity ensued.
Will it change in the case of C.L. "Butch" Otter, the U.S. representative now running for governor of Idaho, who has pulled out of Thursday's primary debate? Probably only if enough people get vocal enough about it. But if the outcomes of the primary and general elections seem a lock - as to many people they seem to be - will that be enough in Otter's case? (In Kulongoski's case, the outcomes seem not nearly so locked.)
It is true that Otter's primary opponent, Dan Adamson, has only the most distant of odds of winning; Otter will probably crush him in the primary. Adamson's campaign has been imaginative and shown some energy, but Otter is the heavyweight favorite. Otter could have said, with some honesty, that the Adamson campaign simply wasn't rising to the point of serious contention, and he's not going to debate every sliver candidate in the field. If that was the concern.
Or maybe the concern is that while Otter is on track for an easy primary win, a primary debate might raise some embarassing issue or idea or fact that could haunt him later. Or maybe he simply didn't want to bother prepping for a debate in a race he knows he'll win easily anyway.
What's reasonably certain is that calendar conflicts did not underlie the pullout, since he was offered three different dates for the event, and none were suitable. If appearing at the debate was a priority for Otter, he could and would make it happen.
We've said before and we'll say again: No official duty should take precedence over reporting to the boss - that would be us - and explaining one's work on the job face to face with the boss's alternative for handling the job in the next cycle. If sitting presidents can find the time to do it - as every one of them has over the last 30 years - surely a member of Congress could manage to show his employers the same courtesy.