So ... why would he do this?
Any clues in the article?
This is an Associated Propaganda article after all.
Oregon state Rep. David Brock Smith, a Republican from southwest Oregon, said Friday that he wants to succeed Heard.
“Stormy” == media code for “conservative, therefore we hate him, and we’re thrilled to have helped force him out”. Heard qualifies as conservative, at least by Oregon standards.
Smith (the guy who wants to replace him) is, no surprise, a typical GOP squish. Senate District 1 is solidly Republican, which means it can do better than a squish — if an actual conservative who wishes to run can be found, and who can compete against all the establishment $$$ and other support which will heavily favor the liberal Republican.