The ad running against Rep. Dennis Rehberg (R-Mont.) features five Montana firefighters sharing with the camera Rehberg's past history with the local fire department in Billings, Mont. Rehberg sued the city after a wildfire devastated his land, and though he eventually lost the suit, it cost the city thousands. The firefighters explain that fires are dangerous and unpredictable.

"So I couldn't believe it when Congressman Dennis Rehberg blamed the fire department for damage to his property," says firefighter Dan Cotrell.

It's an issue that's become central in one of the closest fights in the nation, and one that featured prominently in a scorching ad from the DSCC last week. This new ad takes a somewhat softer approach in its use of local firefighters.

At the end, three firefighters charge that Rehberg is "just out for himself."

In Nevada, the DSCC targets Sen. Dean Heller (R ) on women's issues with an ad in the style of a children's cartoon.

"See Dean HellerDean Arthur HellerDemocrats search for 51st net neutrality vote Nevada Dems unveil 2018 campaign mascot: 'Mitch McTurtle' Senate campaign fundraising reports roll in MORE. See Jane Nevada and her healthcare team," a narrator says over a stick-figure drawing of Heller and a woman.

Heller "erases" her healthcare team -- the ad cites his votes to "reduce access to preventive medical services" -- and her pocketbook, which symbolizes what the ad characterizes as his vote against equal pay legislation. She, in turn, enters a voting booth to "erase" him.

Heller's been running slightly ahead of Rep. Shelley Berkley (D-Nev.) in most recent polls, but the DSCC has been on the offense against Heller for some time in hopes that it can boost Berkley to a win.