U.S. Rep. Tim Walz bagged another endorsement last week, this one from carpenters, which continues a string of building-trades support that includes the International Union of Operating Engineers Local 49 and the Laborers.

His path to the DFL nomination for governor is easy to discern: money, endorsements and organization, all of which propelled him to a caucus straw poll victory earlier this month.

But he's by no means the only candidate with a path. After all, 70 percent of caucusgoers supported someone other than Walz or no one at all.

The campaign of state Rep. Erin Murphy, DFL-St. Paul, thinks that as the pool of delegates is winnowed, her position will become stronger despite a third-place showing at the caucus. Her campaign cites DFL data showing that after 34,000 came to caucus night, fewer than 20,000 will participate in Senate district conventions, which are the next round on the way to the state convention. (Think of it as the semifinals.)

What really matters is the makeup of the 20,000. Murphy's campaign questions whether Walz's caucus support was soft and the result of his higher name ID. In this telling, support for Murphy and State Auditor Rebecca Otto was more enthusiastic and willing to move on to the next round.

The claim is important because a strong showing at a given precinct caucus might not translate into convention delegates if you can't get your people to burn a couple of Saturdays at deadly dull political meetings.

In the end, more than 1,200 delegates will be at the state convention in June, and many will be party hacks who wind up at the convention every two years. Murphy has been working those relationships for a long time.

"As we head into this part of the race — attending conventions all over the state and talking with delegates — we know that Erin has the edge because of her ability to connect with people and her incredible work ethic," spokeswoman Jessica Nyman said in an e-mail.

Otto's pitch is ideological. She sells herself as the most progressive candidate in the race, with clean energy and health care proposals that would earn the approval of someone like U.S. Sen. Bernie Sanders.

During a week consumed with conversation around school shootings and gun control, she took the fight to Walz, who proposed an assault weapons ban this week, saying he was too long in the sway of the National Rifle Association.

Soon enough we'll know if it matters to the delegates.

J. Patrick Coolican • 651-925-5042 patrick.coolican@startribune.com Twitter: @jpcoolican