The 34-year old Curtis, who faced poverty and tragedy growing up, is a relative newcomer to politics. She won her first election in 2012, easily taking the nomination in a Butte-area seat. Curtis was unchallenged in the general election in this district, which Obama carried 70-27. Curtis decided to retire from the state House after redistricting placed her in the same district as another Democratic incumbent. However, she'll be on the November ballot after all, albeit in an unexpected way.
Curtis has a very uphill climb here. Freshman Republican Rep. Steve Daines, who represents the entire state, was consistently leading Walsh even before the plagiarism scandal broke, and will be hard to beat in this conservative state. Curtis will be starting this race with virtually no name recognition and no money, and will need to work very quickly to raise both. If Curtis can get organized in time, she may have the chance to do well. Daines is not particularly popular, sporting a 39-40 approval rating in a July Public Policy Polling survey. Curtis is also not a member of a horrifically unpopular Congress, which could help her in a close race. However, it won't matter much if Curtis cannot get her name and message out. Daily Kos Elections rates this contest as Likely Republican, and Curtis definitely has a lot to prove.
National Democrats haven't spent much here since Walsh's campaign imploded: If they feel Curtis can make this a race, they'll probably want to act fast to raise her profile or attack Daines. It will also be interesting to see if Republicans and their allies decide to attack Curtis before she can respond, if they decide to boost Daines instead, or if they feel that they've already won and do nothing. We'll know soon enough if either side believes there's a contest here or not.