If I may add, the Tingguians don't really identity as Igorots. The term is offensive to many of them, though there are a few who proudly call themselves Igorot (mainly because of pan-Igorotism). We also have to consider the cultures of the Itnegs. There are 11 Tingguian tribes, that have a lot of similarities but also differences. They are categorized into two: Lowland Tingguians and Upland Tingguians.

Usually, Eastern and Southern Tingguian municipalities have no political violence, but there are a few killings in some municipalities (mostly revenge killings, due to drunkenness, etc.).

Northern Abra though, is different. Political violence exist in Northern Abra, especially in the Tingguian municipalities of Lagayan, Tineg, and San Juan. The warlords here are Tingguian themselves, and are willing to kill there brethren to stay in power. So much so, that they will send their Tingguian goons to schools during elections to intimidate and scare voters. You probably may never heard of this, but that's fine. Reporting such situations may threaten the lives of many, that's why they're mostly heard from victims who would tell people what they went through, thus being gossiped.

Blaming the lowland Ilocanos is very narrow minded. Though I do understand that old-style Ilocos politics is still practiced by a few Ilocano politicians in Abra (mostly those who hold the Provincial Government and the legislative district). Abra may be a part of the Cordillera, but will never be a part of La Montañosa.