The field for the 2010 election in North County's Congressional District already is taking shape, with two Democratic candidates actively campaigning, either raising cash or soliciting endorsements, and taking shots at incumbent Republican U.S. Rep. Brian Bilbray.

And a third Democrat seems poised to jump into the fray next month.

"The Democrats took most of the seats they could expect to get in 2008," UC San Diego political science professor Gary Jacobson said. "Now, they're looking for districts where they think they can pick up even more, and they see the 50th as just such an opportunity."

Leading the trio of Democrats is Francine Busby, a former school board member who lost to Bilbray in a special election in June 2006 and was walloped by him again in November of that year.

She nonetheless already has racked up several endorsements from prominent Democrats in the region.

New to the fray is Tracy Emblem, an Escondido criminal appellate attorney, who says she's prepared to raise and spend as much as $500,000 to win the Democratic primary.

The third emerging candidate is Solana Beach City Councilman Dave Roberts, a former Bilbray supporter who also spent time working on Capitol Hill.

He describes himself as a conservative Democrat who can win over a changing electorate in the 50th, which has long been a Republican stronghold.

Bilbray, who defeated Democrat Nick Liebham by 5 percentage points last year, dismissed the early jockeying among Democrats.

"There's a lot of people who have time on their hands while I'm here working on substantive issues," the 58-year-old congressman said, adding that it's too early for him to worry about 2010.

During an interview last week, Roberts said he won't decide until late July whether to formally enter the race.

Roberts then spent several minutes outlining reasons why he believes he would make a good congressman.

Driving the early campaigning for the Democrats is Emblem's December announcement that she would run.

That prompted Busby to declare a short time later that she was in again. And Roberts says he has been approached by several people encouraging him to capitalize on his Washington experience.

Adding fuel so many months before the first vote is an assessment by the Democratic Congressional Campaign Committee that Bilbray is vulnerable in 2010.

Three weeks ago, the group that raises money and helps with the campaigns of Democratic candidates sponsored a series of radio ads and telephone calls to voters criticizing the former county supervisor and Imperial Beach mayor.

Party operatives also point to Barack Obama carrying the district presidential vote in November, a rising number of Latino and registered Democrats and independent voters, and Bilbray's votes against the stimulus package and equal pay for women.

The National Republican Congressional Committee, the Democratic Congressional Campaign Committee's counterpart, appears to have made the same type of assessment, placing Bilbray on its "Patriot" list and announcing this month that it will organize fundraisers and commit its resources to his re-election effort.

The committee's Web site features Bilbray and says it will begin its fundraising efforts Wednesday with a "Patriot Day" in Washington, featuring GOP leaders and members in the House of Representatives.

The numbers

What was once a Republican majority of 15 percent in the 50th District is now down to 9 percent, adding to the Democrats' belief that they have a chance to take what has long been considered a safe GOP seat.

As of May, Republicans constituted 41 percent of the electorate, compared with 32 percent registered as Democrats.

The pool that Democrats say they can capture is the nearly 25 percent of district voters with no party affiliation, something that UC San Diego's Jacobson says is a distinct possibility.

"There's no question the Democrats see an opportunity," he said. "What used to be a large majority of Republicans has narrowed, and the independent-voter crowd tends to favor Democrats."

Jacobson said he questions whether Busby is the Democrat who can turn the district upside down.

"She spent millions in 2006, and it wasn't a terribly encouraging campaign," he said.

The candidates

Busby, 58, said she believes that the changing nature of the district and her name recognition from her earlier runs gives her an advantage over other Democrats.

"I'm in this again because I truly believe I have a vision for what people in this district care about," she said. "Brian Bilbray represents only the Republican Party and the continuation of the broken polices of the Bush administration."

She said his vote against the Obama economic stimulus plan was a "cynical" choice because he knew the measure would be passed by the Democratic majority in the House and Senate, and that funds would be headed to the region as a result.

"He also continues to talk a hard line on immigration, but has done nothing to further the agenda on that issue for some real reform."

Emblem, 54, an Escondido resident since age 8, is making her first run for political office, a decision made the day after the November general election, she said.

"Francine is a very nice woman, but I don't believe she can carry the district," said Emblem, whose daughter, Erin, is drawing on 17 years of political fieldwork experience to manage her mom's campaign.

Emblem describes herself as a moderate to conservative Democrat whose focus in Congress would be on jobs, health care and the economy.

Like Busby, she favors a pathway to citizenship for illegal immigrants, a proposal that Bilbray strongly opposes.

Emblem promised that she will conduct a "community-based" campaign and will offer solutions to issues.

"I'm a lot more moderate than Francine, and if we're going to beat Brian Bilbray, we're going to have to be smart about it," she said. "He didn't become a career politician by running stupid campaigns."

Roberts, 48, spent time in Washington in the 1990s as a Senate staffer and working for the House Appropriations Committee.

A one-time Bilbray backer, Roberts said that several people have encouraged him to run.

"I'm a conservative Democrat and former mayor and current council member," he said, adding that Democrats and nonaffiliated voters are looking for a viable candidate who can bring change.

Count some Republicans among those unhappy with Bilbray, he said.

"A lot of Republicans don't like Brian," he said. "They consider him a carpetbagger who came up from South County in 2006, and they're disappointed in a lot of his votes."

Bilbray said he still counts Roberts as a friend, even if the two no longer agree on policy.

He also contended that he does not follow the party line, despite a voting record on major policy and fiscal issues that suggests otherwise.

"I have never relied on party," he said. "I spent too many years as a local elected official to do that."

Bilbray had $88,000 in his campaign account as of March 31, a total that is certain to swell from the proceeds of his upcoming fundraiser.

Emblem has raised $24,000 thus far, including a $19,000 loan to herself, according to federal campaign election records.

Busby has formed a 2010 election committee, but has not yet reported any contributions.

Call staff writer Mark Walker at 760-740-3529.