Many indicators say "yes".
This morning, Bowen tweeted
On Saturday, Bowen publicized her "exploratory committee" website, asking for constituent input on wether she should run. And all weekend I've been hearing reports of CA-36 voters being polled via robo-call about the race. Separate reports I've received say that Bowen and her campaign manager, Park Skelton, are waiting on poll results before making an announcement on Tuesday.
Potential candidates are rarely this public about entering a race without actually following through. So I'm going to go out on a very short limb and say by this time tomorrow it's likely we'll have two official Democratic candidates competing for Jane Harman's seat, Debra Bowen and Janice Hahn.
Hahn, who announced within hours of Harman's resignation, has been busy locking up a number of high-profile endorsements, including LA Mayor Antonio Villaraigosa, Councilman Bill Rosendahl and California Assembly Speaker John Perez.
Just this morning, she received the highest-profile endorsement to date, from CA Senator Diane Feinstein. (However, this endorsement is probably a lot more about marginalizing Bowen, who has been touted repeatedly as a possible challenger to Feinstein in 2012, than it is about helping Hahn.)
Bowen has the defacto support of California progressives and California Democratic Party Chairman John Burton, who sent out an email on February 7th claiming Bowen was the only person to "officially inform" him they were running for Congress. This even though Janice Hahn had announced earlier that same day she was running. It sets off an interesting dynamic, with politicos in Sacramento and Los Angeles taking sides in a race outside their district.
How this will translate into votes inside the district is unclear. But in another race a with similar (but far from identical) dynamic, the 2010 Democratic primary for Lt. Governor, Janice Hahn beat Gavin Newsom by 9 points in CA36. This was actually lower than the spread for LA County, where she beat Newsom by 30 points.
All of this points to a very competitive race, where both candidates will have to work very hard in a very short amount of time for votes and money in an off-year election where few are paying attention.
With Harman's resignation set for tomorrow, Governor Jerry Brown has until March 1st to set a date for a special election to fill Harman's seat. According to Janice Hahn, the primary election will likely be held on April 12, with a general election coming sometime in June.
The special election primary will be held under new "open primary" rules. Voters can select any candidate, regardless of party affiliation. If no candidate gets 50% +1, the top two vote-getters will have to run against each other in a June runoff.