With ballots in the mail-only “jungle” primary set to go out this week and five Democrats battling for a spot in the top two, the pace and intrigue of the open-seat 1st district race have picked up considerably.

The Seattle Times reported Sunday that the mother of former state Rep. Laura Ruderman, one of the Democratic candidates, funded a super PAC working against one of the party’s frontrunners, former Microsoft executive Suzan DelBene. Then Ruderman’s campaign released a TV ad Monday that features her mother, who is battling cancer.

On Tuesday, state Sen. Steve Hobbs (D) released an internal poll showing him, DelBene and former Microsoft manager Darcy Burner essentially tied for second place behind Republican John Koster. As the lone Republican in the top-two primary, Koster is all but assured of advancing in this swing district.

Burner is distributing a 12-page “magazine” mail piece this week that highlights her views and ideas, plus a crossword puzzle. And, in a display of just how fractured the redrawn 1st district is after redistricting, Koster announced Tuesday the hiring of a campaign manager dedicated solely to King County, where about half of the district’s residents reside. Valerie Huntsberry will manage all of Koster’s campaign operations south of the Snohomish County line.