The field for Philadelphia's next mayor was unexpectedly reshuffled Wednesday when Ken Trujillo announced he was pulling out of the race because of "family matters that require my full attention."

A campaign source said the personal issue involved Trujillo's extended family in New Mexico. Trujillo, through an aide, declined to address the matter beyond a statement released by his campaign.

Trujillo's withdrawal from the Democratic mayoral primary caught the political community off guard and significantly changes the calculus of the campaign, creating a vacuum that is certain to tempt others to consider entering the race.

"I know the phone lines are burning up," said Dan Fee, a Democratic political consultant not aligned with any current mayoral candidate. "There is still no real progressive candidate, no one with business experience. No one with substantive experience in city government."

Trujillo, in his statement, said he was ending his candidacy "because I believe strongly that we must leave the door open for another candidate to enter this race. Philadelphia needs someone who has the skills and values to put Philadelphia first, and I very much hope voters will have such an option."

A campaign source said the former city solicitor did not believe any of the remaining candidates filled the bill. The source said Trujillo was prepared to put up his own resources - upward of $3 million - to advance the chances of the right candidate. He also will take an active role in recruiting that candidate, the source said.

"He is not at all confident in the current field of candidates," the source said. "He's engaged in conversations about getting the right person in."

At the moment, the campaign is left with three announced candidates - State Sen. Anthony H. Williams, former District Attorney Lynne M. Abraham, and former Common Pleas Court Judge Nelson Diaz. Doug Oliver, former spokesman for Mayor Nutter, and former State Sen. T. Milton Street Sr. have said they intend to run, but have not formally announced.

Williams, Abraham, and Diaz all issued statements of condolence following Trujillo's withdrawal.

While not considered a front-runner, Trujillo was putting together a formidable campaign operation. In the last two weeks, he had hired a field director, political director, and policy director, according to campaign spokeswoman Lauren Hitt.

The source said the decision to withdraw was driven by circumstances that arose only in the last several days, catching his campaign by surprise.

Trujillo had based his candidacy on being something of a political outsider who could attract support from the progressive and business communities. Trujillo, who has an established law practice and owns a Spanish-language radio station (El Zol, the old WHAT-AM), was prepared to invest a portion of his own wealth in his election bid.

He was seen as having the potential of surprising the field's most established candidates, Williams and Abraham.

"He was the wild card," said City Controller Alan Butkovitz, who is weighing the possibility of jumping into the race himself. "This certainly creates a vacuum. I suspect there is going to be a lot of confabbing going on about what can be put together with time there is left."