Oregon constitution
Article IV: legislative branch
Section 15

Either house may punish its members for disorderly behavior, and may with the concurrence of two thirds, expel a member; but not a second time for the same cause. Failure to attend, without permission or excuse, ten or more legislative floor sessions called to transact business during a regular or special legislative session shall be deemed disorderly behavior and shall disqualify the member from holding office as a Senator or Representative for the term following the election after the member’s current term is completed.