To understand the conflict facing black Democrats -- of choosing between the established female candidate and the promising African-American newcomer -- go no further than Pittsburgh City Council, where the two black council members are splitting their allegiances.

Their split also highlights the strain between the city's Democratic political establishment, black and white, which largely supports Sen. Hillary Rodham Clinton in the April 22 primary, and a black voter bloc that is expected to line up behind Sen. Barack Obama in 11 days.

District 6 Councilwoman Tonya Payne is both a prominent African-American leader and an advocate for Mrs. Clinton. Part of her support comes from good memories of President Bill Clinton's two terms and part comes from a sense of realpolitik.

"The objective here is to win the seat -- to actually have a Democrat in the White House come January. Both Obama and Clinton are good candidates -- superb candidates -- but I just see Clinton being stronger in the General Election and winning against McCain," Ms. Payne said, in a break from a council session Wednesday.

"I say that because of the experience Clinton has, the races [she has] actually run and won in against Republicans, and Obama doesn't share the same [experience]," she said.

That argument gets a rise out of District 9 Councilman Ricky Burgess of Homewood, a supporter of Mr. Obama.

"All during this campaign people have said what he could not do. He could not win Iowa, but he did. He could not be the nominee, but he will be. I think it's a little disingenuous to say he cannot be strong in the general election," Mr. Burgess said.

"Show me some evidence that that [success] will not continue," he continued, pounding a council conference table for emphasis. "We see in every state the polls go up, up, up. I think between now and the general election you'll see the same phenomenon."

Each fall, Allegheny County's black voters have supported the nominated Democrat in general elections 97.5 percent of the time, according to an analysis by University of Pittsburgh economist Chris Briem of the University Center for Social and Urban Research.

But in primaries like the one April 22, all bets are off. His look at voting patterns in 1999 and 2001 showed that local African-American Democrats do not always support the party-backed nominee in primaries.

That happened in the May 2001 primary for the Allegheny County Council District 13 seat, when large majorities in black neighborhoods delivered a win to Brenda Frazier, despite her not having the party machinery's nod and not winning majorities in mostly white communities.

On the very same day, black voters failed to unify around a choice for mayor, helping hand a close victory to incumbent Tom Murphy in his second match up with Bob O'Connor. With just a bit more support from largely African-American wards in the Hill District, Larimer, Lincoln-Lemington and Homewood, Mr. O'Connor could have won that year. (The late Mr. O'Connor would take most of those wards during his winning run four years later.)

Those same largely black wards gave Democrat Luke Ravenstahl -- another Clinton supporter and member of the party establishment -- some of his largest margins citywide in his special election in November against Republican Mark DeSantis, according to another of Mr. Briem's studies.

Again, that points out the difference between what can be expected this month and in November. In primaries, local black Democrats are more likely than usual to go for a newcomer like Mr. Obama over the party establishment-supported candidate, Mrs. Clinton. By the end of the year, it's back to the straight Democratic ticket.

"People confuse the general election with what happens in the primary. People got bent out of shape by the [black vote in the] mayor's race, saying Luke [Ravenstahl] got the so-called machine, but it's more complicated than that," Mr. Briem said.

The economist's research backs up the one thing Mr. Burgess and Ms. Payne agree upon: that most local black voters will vote Democratic in November and not for likely Republican nominee John McCain out of spite if Mr. Obama loses.

Still, Mr. Burgess had one warning for the party if Mr. Obama, who so far leads in the popular vote and pledged delegate counts, is passed over, perhaps at the party convention in August.

"It would be a fatal flaw for this country to disenfranchise the majority of Democratic voters and steal this election from Barack Obama," he said.

Ms. Payne has faced heat lately for her Clinton support in the editorial pages of the New Pittsburgh Courier. In an April 2 piece titled "What to do with Tonya Payne?" Lou Ransom, the paper's former managing editor and a supporter of former Councilman Sala Udin, whom Ms. Payne defeated in 2005, wrote: "Payne, obviously, would not vote for a black man."

The councilwoman responded with her own Courier piece, mentioning that she donated to the Obama campaign before his surprising victory in the Iowa caucuses, but that she chose Mrs. Clinton based on experience rather than skin color.

She said she knows she's in the minority in her district, covering the Hill District and part of the North Side.

"The majority feel this is the first time that we ever had an individual from our race who has such a great opportunity of becoming president of the United States -- that's something to be really proud of, and I'm proud of it too," she said. "Trust me, whoever the nominee is, I'm going to work my heart out for that nominee."

Ms. Payne is the local Democratic Party's 1st Ward chairwoman, and among those in the party apparatus wary of turning off longtime supporters in the black community by supporting the Clinton campaign too vocally. That is partially why county Democrats did not issue a formal endorsement of Mrs. Clinton, even though it did support her in a straw poll and she has the support of the Democratic committee's chairman.

Politics, especially among black voters, is all about the nontraditional this year, said Mr. Burgess.

"This election will not be about a normal, endorsed candidate. Barack Obama is one of those unique figures in American history that transcends normal politics," he said. "For African Americans he is such a strong symbol of hope and of possibility that it will be virtually impossible to keep that vote from surging."