You have to suspect that the entry in the Oregon 4th of Springfield Mayor Sid Leiken is premised on (a) an open seat or (b) building for the future.
By all accounts - and this is a guy Oregon Republicans have wanted for years to run for higher office - Leiken will be a serious candidate and a real part of a generally limited Republican bench in Oregon. As Roll Call, which broke the announcement (hat tip though to Jeff Mapes at the Oregonian) suggested, "a run against DeFazio may seem like a fool’s errand."
That would be Peter DeFazio, the Democrat who has held the 4th district seat since 1986, and won in landslides every election in the last 22 years. And that district, which has been described as lean-Republican in the past, now leans Democratic. On rare occasion, a long-time member of Congress will be defeated, but that usually happens upon becoming neglectful of the home district, something DeFazio doesn't do.
So how would this make sense? We'd suggest, two ways it could.
First is if DeFazio decides to run for governor, opening the seat. He has not ruled out a gubernatorial run and has expressed some interest. If the seat opens, an early-early start by a decent candidate like Leiken could situate him well.
Second consideration is that, after such a long run, DeFazio won't be there forever, and sometimes an initial run for an office can help pave the way for another one later - or for another major office.
Leiken's race will, in any event, be worth some attention, more than most Republican candidacies in the 4th have been for some time.