I generally say that more heavily Hispanic areas in Oregon have trouble with turnout. Below I use maps and charts to illustrate my research into whether I am truthful in asserting that.
Oregon's Hispanic populations are heavily concentrated in a few areas. Below is a county map of the Hispanic population as a portion of the total population (according to the 2010 census), with darker counties being more Hispanic and lighter counties being less Hispanic. The darkest, Hood River, Morrow, and Malheur, are near or above 30% Hispanic, while the lightest, such as Baker and Wallowa, are perhaps 2-4% Hispanic.
I then turned to look at how each county's voter registration in the 2010 election compared to that county's voting age population in the 2010 census, with counties with high registration rates being lighter, and low registration rates being darker. This is where there began to appear more in common between high non-white populations and low registration rates. While in between there was more variability, the counties with the lowest non-white populations had the highest registration rates, and those with the highest non-white shares of populations had the lowest registration rates. For example, Gilliam County has one of the lowest non-white populations, but over 80% of adults were registered to vote. In Jefferson County there is the largest non-white population, and fewer than 59% of adults were registered to vote. In heavily Hispanic Malheur County little more than 52% of adults were registered to vote.
It is reasonably inferred from this that because places with higher non-white populations tend to have lower voting participation than counties with higher white populations, especially at the extremes, most of the lack of participation comes from non-white Oregonians themselves. Part of this is because they are more likely to be immigrants who lack voting rights, part of this is because they are more likely to be incarcerated, and if so then they do not have the franchise until released. A significant part of it must be because fewer who could participate are doing so, however.
Every county in the state has a higher non-white portion of the population among those under 18 years of age than among the adult population. In many counties the under 18 non-white population is double the size of the adult non-white population as a share of the whole.
In Washington County the non-white share of the under 18 population is 42%. In Multnomah and Umatilla counties, its 44%. In Marion County it is nearly 48%, in Hood River it is just a hair below 50%, and in Morrow and Malheur it's over 50%. Malheur County's white population actually shrank between 2000 and 2010, while its Hispanic population grew significantly. In Jefferson County over 61% of the under 18 population is non-white. Even on the Coast, which tends to be whiter than the state, every county's under 18 population is at least 20% non-white, and in Lincoln County it is 30%.
This is not only in Hispanic populations, as generally across most communities the Asian American, African American, Hispanic, and Native American populations as well show higher portions among under 18 populations than among adult populations.
Incarceration may be significant causes of low participation in some places like Umatilla and Malheur counties which have state prisons, and so may have their non-white populations inflated from incarcerated prisoners, but that does not explain why the under 18 non-white populations re so large. As well, while those counties have a lot of immigrant workers who lack the right to vote, the under 18 populations should have much higher rates of citizenship because more were probably born here. Lack of participation among the smaller adult populations may not mean that the larger, younger non-white populations will have the same problems preventing participation.
If the same obstacles persist, counties across Oregon will see much lower participation rates in elections as the non-white share of the population grows. If they do not persist, Oregon will be a very different place in 30 years than it is today.
There are two different kinds of trends to consider when weighing the potential of an increasingly non-white electorate: statewide and local.
If most of the places where there are large percentages of people not voting are places where there are high non-white populations, most of the non-voters are likely non-white. Because of how demographic groups vote, this makes it appear that most of the people who aren't voting would vote Democratic. If that is true, and if it is true that Oregon is becoming less and less white every year, and so is the electorate, then Oregon Republicans need to do one of two things in order to keep from falling further and further behind: do much better among non-white voters, or do much better among white voters. They really have few untapped white voters outside of Linn and maybe Klamath counties.
The non-white populations tend to be concentrated in certain areas. The African American population is concentrated in portions of North and Northeast Portland. The Asian American populations are concentrated in outer east Portland, especially around 82nd Avenue, as well as the Washington County suburbs, especially north of Highway 26. Native populations are concentrated around reservations and communities in Yamhill, Polk, Umatilla, Klamath, Lincoln, Wasco, and Jefferson counties. Large Hispanic populations are in Umatilla, Morrow, Malheur, Jefferson, Hood River, Marion, and Washington counties, with pockets in other places like White City in Jackson County.
In recent elections many of these counties have trended Democratic, like Multnomah, Hood River, Washington, and Malheur. However, many others have trended Republican, like Umatilla, Morrow, and Wasco counties. As well, some of the whitest counties in the state, sparsely populated Wheeler and Gilliam, seem to be trending Democratic in recent years. It seems unclear if some of the trends are due to growing non-white populations or not.
If non-white participation increased significantly, Hispanic Oregonians in particular could become empowered in many communities, and could become pivotal voting blocs or even dominant in places like Woodburn and Salem, Hillsboro, Cornelius, Beaverton, Hood River, Hermiston, Ontario, and Madras, even in Portland and even in communities on the coast. But it could also lead to turning some Eastern and Central Oregon counties blue, and retaining Democratic strength on the coast. Malheur County is one of the reddest in the state, but it is hard to imagine Republicans winning by more than single digits there in a couple decades, given current trends and so long as participation among Hispanics there rises to near that among non-Hispanic whites.
Recently many local communities in Eastern Oregon and the Columbia River Gorge have been supporting pro-immigrant policies at the state and federal levels, even some in deep red and Republican-trending Umatilla County. Many farmers and residents have been pressing Greg Walden to vote for immigration reform, and many of the Republican state legislators in those areas voted to allow undocumented residents to have temporary drivers licenses and allow them to use in-state tuition (statewide, Republicans are still the main opponents to pro-immigrant legislation). However, as non-white populations boom we may see increasing racial polarization in some traditionally Republican and white-controlled counties, and we may see increasing efforts to prevent non-whites from voting, as Republicans are doing in places like Texas and North Carolina.
Efforts to increase participation of the non-white populations across Oregon must include supporting Comprehensive Immigration Reform with a path to citizenship. Low citizenship rates among many immigrant residents of Oregon is likely one of the biggest barriers to raising participation. Other things that Oregon could do to try to improve participation is legalizing marijuana, which should lead to fewer people being incarcerated for drug crimes, or passing a state voting rights act to prevent counties or other locales from affecting their election laws or procedures in ways that will target minority populations.
Oregon Democrats in particular, both party organizations and politicians, should reach out to non-white communities across the state and aid their own community groups in efforts to increase their political power and participation. There have already been some efforts like this in some places, but there is obviously more work to do, especially in certain communities like Chiloquin, Warm Springs, and Gervais where there are extremely low participation rates. While it is unlikely that this would turn all of Southern and Eastern Oregon blue, given the extremely concentrated nature of these populations, it is possible that there could be a state house district or two that could flip on account of increasing participation rates in 10-20 years, and statewide it would be a big boon for Democrats in continuing to keep Republicans locked out of statewide office.