Another African-American judge, C. Darnell Jones 2nd, withdrew as a potential candidate in favor of Massiah-Jackson, judicial sources said. Jones did not respond to a request for comment.
Three other candidates, John W. Herron, William J. Manfredi and Eugene E.J. Maier, are white.
The president judge's job carries with it both ceremonial duties and budgetary responsibility. While its chief attraction is the prestige it carries, most of the real power is exercised by the administrative judges who have authority to hire, fire and make assignments in the court's three divisions.
The post pays $2,500 more than the $113,789 that regular Common Pleas judges receive.
Twenty-one of the 84 judges eligible to vote for president judge - 25 percent - are black. There are 24 Common Pleas judges in the Judicial Council, which includes judges from other minority groups.
There are six vacancies on the court, with two nominations pending in Harrisburg. If those nominees are confirmed in time, they will be permitted to cast ballots.
Court rules specify that the president judge can be elected with a plurality of the vote.
One judge, who asked to remainanonymous, said he was troubled by the Judicial Council's apparent decision to vote as a bloc.
"The Jewish judges are the largest ethnic group on the court, and if we agreed to vote as a bloc we would be severely criticized," the judge said.
Judge John Younge, chairman of the Judicial Council, said the members of the council voted to support Massiah-Jackson because she shared their views on matters of importance.
Several judges said Massiah-Jackson's election is far from a sure thing. They said they believed that Herron, 56, now an administrative judge, should be considered the favorite.
"Herron's been in charge of court operations for five years and he's done an excellent job," said one judge. "He's not the most popular guy because he's firm and strict, but he's fair."
Massiah-Jackson, Herron, Manfredi and Maier all confirmed in interviews that they are seeking to win the president's job.
The winner would succeed Alex Bonavitacola, whose five-year president judge term ends in January.
Manfredi, a judge for 17 years, said he would use the presidency to build respect for the justice system. A friend and business partner of state Sen. Vincent J. Fumo, Manfredi said he "would welcome the support of political figures outside the court."
"As of now, I have no firm commitments of outside support," said Manfredi. "But this is an election among judges and I don't know how helpful that kind of support would be. But this is a darned good court and it will remain so no matter who gets elected."
Massiah-Jackson, a judge since 1984 and the elected secretary of the Board of Judges, said she has received promises of support from other female judges and white judges as well as from the minority Judicial Council. She also has outside support from J. Whyatt Mondesire, president of the local NAACP.
Herron, elected a judge in 1987, was appointed administrative judge of the Trial Division - the largest of the court's three divisions - by the state Supreme Court in 1996. In that post, he was the most powerful person in the judicial system, with responsibility for hiring and firing personnel and assigning judges in both the criminal and civil courts.
"I agree with Judge Manfredi that this will continue to be a darned good court, no matter who wins," said Herron.
Maier, a judge since 1982, said if his colleagues voted for him, he would be "interested in serving."
The election is by secret ballot. The names of all judges eligible to serve as president judge will be on the ballot.