Timmer, online here and here. While Dayton's choice of Tina Smith arguably was a brain fart, it ended people pulling on his sleeve for the nod. Smith is entirely on her own now; Dayton's star is setting. Timmer going that way was not unanticipated, from the first post about Painter by Timmer, (commenting on a favorable Painter session impression at a Drinking Liberally event), onward.
A big SO WHAT: Mondale notice was via a Walz campaign email, so there is no link to give. It is not exactly as if Walz got an endorsement tap from a progressive.
MPR, here and here.
If you move on to read all the links and to search about Mondale, do not be surprised if you learn nothing from doing so. This is all information. None of it is earth shaking.
Having already voted my absentee ballot, and not wanting to say much against somebody who might end up a primary victor taking on some Republican creep, I shall keep personal preferences private until after the primary vote.
The main hope is progressives winning primaries; and then the Republican creeps being defeated in the general election.
The one fact progressives know; Republicans are not progressives, not near to such insights; and that once we go from primaries to the general election goals will be easier to see in terms of then remaining options. That would be a time to endorse.
Finally, the single most important fact about Richard Painter is MPR reporting that if sent to DC as Minnesota's senator he has committed that he would caucus and vote on committee assignments and other organizing with Democrats. That can be called the Collin Peterson point of view; not great as a reassurance but better than if Painter had said he'd caucus Republican.
____________UPDATE____________
Interesting reporting today was from MinnPost, about Ellison and this study.
More coverage - Strib in a "Judy Keen Star Tribune July 31, 2018 — 4:08pm" item says Ken Martin thinks Painter is a "wolf in sheeps clothing." Publically calling Painter that, Martin may use other terminology in private.