This is bad news:

New Hampshire Governor Maggie Hassan, a Democrat, announced Monday morning that she will challenge first-term US Senator Kelly Ayotte in 2016, setting up what will likely be next year’s most competitive Senate race in New England and the most high-profile Senate race among two women in US history.

For months, polls have shown a hypothetical matchup between Ayotte and Hassan to result in a statistical tie. Democrats must win a net of at least five US Senate races in 2016 to take control of the Senate.

Hassan has twice won the governorship.  Dems were working her hard to get her to go for this race.  Hassan’s husband is the headmaster at Phillips Exeter. 

The U.S. House races in New Hampshire regularly turn over from one party to the other (the GOP tends to win in off years).  There is not a huge advantage to incumbency for Ayotte.