There are some buttons that his campaign produced in the early years. All that I have picked up are badge-a-mint produced by a local supporter named Wayne Anderson. For a long time all I had known about was a 2.25" version. Just this last week I was able to find a 3" version as well!
In 2016 Greenlick wrote a book called Capitol Letters: An Inside View of the Legislative Process. He writes about his involvement in politics, parties, and the legislature. Greenlick is Chair of the House Healthcare Committee and has pushed for a number of healthcare policies over the years drawing on his long career working in healthcare research and administration. There is a forward by Congresswoman Suzanne Bonamici. One of the telling things that reveals a little of Mitch Greenlick's personality is he comments 'debating is fine, but passing bills is finer'. I picked up a copy of the book at an event and had the author sign it for me.
Here is a video from the Oregon Capitol where Mitch Greenlick gives a talk moderated by Oregon Historical Society Executive Director Kerry Tymchuk.
I'm still looking for other Mitch Greenlick items. He ran for Beaverton School Board in the 1970s. If you have any Mitch Greenlick items feel free to send us an image.