Rep. Steve DainesSteven (Steve) David DainesOvernight Defense: Senate sides with Trump on military role in Yemen | Dem vets push for new war authorization on Iraq anniversary | General says time isn't 'right' for space corps Senate sides with Trump on providing Saudi military support Overnight Tech: Ivanka Trump gives boost for anti-sex trafficking bill | GOP senators push to keep online sales tax out of omnibus | How James O'Keefe operatives tried to trick tech employees MORE (R-Mont.) is starting off with a big lead in his bid to replace retiring Sen. Max BaucusMax Sieben BaucusFarmers hit Trump on trade in new ad Feinstein’s trouble underlines Democratic Party’s shift to left 2020 Dems pose a big dilemma for Schumer MORE (D-Mont.), according to a new poll from the Democratic firm Public Policy Polling.

Daines leads Montana Lt. Gov. John Walsh (D) 52 percent to 35 percent and has a 15-point lead over former Montana Gov. John Bohlinger (D).

Democrats will have to make up a lot of ground to keep control of Montana's Senate seat, a must-win for the GOP if the party hopes to win the six seats needed for Senate control.

Daines is not beloved in the state — his approval rating sits at 37 percent, with 42 percent disapproving — and Walsh is only known by half of the voters in the sample, meaning his numbers have room for improvement. But President Obama is in terrible shape in the GOP-leaning state. His approval rating is 34 percent, with 63 percent disapproving, a big drop from the 42 percent of the vote he won in Montana in 2012.

Walsh, who has the backing of the Washington Democratic establishment as well as Sen. Jon Tester (D-Mont.), starts off leading Bohlinger in the primary 39 percent to 31 percent. Bohlinger served as a Republican on a joint ticket with former Montana Gov. Brian Schweitzer (D), and officially switched parties for this race.

PPP's automated survey of 952 Montana voters was conducted Nov. 15-17 and has a margin of error of plus or minus 3.2 percentage points.

This post was last updated at 5:05 p.m.