As a Republican looks at the Oregon congressional redistricting picture, the question at hand is this: Is there a way to move the probable partisan split of the (now and future) five House districts from a 4-1 Democratic majority, to just 3-2?
It would seem not too difficult a task, in the sense that Oregon's voting population is close enough that control of 40% of the state's congressional districts ought to be out of reach. It proves a slippery goal, though.
Consider this map, posted on the Republican-leaning RedState site (not recently - this was in 2009) as a GOP option for getting from one to two districts out of five. (H/T here to the correspondent who pointed it out.) A larger version and a close-up of the metro area are available at the link.
The population split looks more or less reasonable, recognizing that it was drawn before the 2010 census was conducted.
One clearly-Republican district is, as now, easy to come by - draw in Oregon east of the Cascades and a slice of population on the west end (that would be the green district). The tricky part is the four districts on the west side. The drafter here was able to craft a district that credibly would be majority-Republican. That yellow district looks Republican and probably would be (the drafter estimates a 9% Republican advantage there). The other three districts would be solidly Democratic; there are no swings.
But see how strained the yellow district looks - using a tiny isthmus to connect interior northwest counties (such as our home of Yamhill, which is close to Portland) with the California border country. It can do that only through bypassing Lane and Benton counties and their mass of Democratic votes - a too-obvious gerrymander.
Study that map for a bit and the difficulties of moving Republican House seats in Oregon from one to two come ever clearer.