With the high-profile race to replace Rep. Major Owens in Brooklyn’s 11th congressional district shaping up as too close to call, the four candidates were scrambling to energize their supporters and to raise last-minute funds in the final full day of campaigning.

The Democratic primary is tomorrow, and unlike the campaigns for Senate, governor, and attorney general, there is no clear front-runner in the 11th, an election that has generated widespread attention for its racial dynamic. A City Council member, David Yassky, has run circles around his opponents in fundraising, but he is the lone white candidate in a district that is nearly 60% black. He has faced relentless charges that he moved into the district with the idea of dividing the vote among the three African-American candidates.

The three other candidates each have points of distinction heading into the election: a council member, Yvette Clarke, has landed powerful union endorsements; state Senator Carl Andrews has the backing of the Democratic establishment, particularly Attorney General Eliot Spitzer, and, not surprisingly, Chris Owens has the support of the incumbent — his father.

Mr. Yassky spent the day yesterday greeting voters at various areas in the district, which includes Crown Heights, Brownsville, and parts of Park Slope. As he has over the course of the campaign, he focused on his experience in government. “I have the experience and the ideas to change policy in Washington, and that’s what this district needs,” he said while campaigning at the corner of Smith and Warren streets in Carroll Gardens. “Washington’s policies have been completely wrong for what we need here, and the voters know that.”

Mr. Yassky’s opponents each had different strategies for victory. Ms. Clarke, who has touted her Caribbean West Indian roots, was focusing on immigrant groups in the district. On primary day, she is banking on the get-out-the-vote efforts of the Service Employees International Union 1199, the powerful health workers union that has endorsed Ms. Clarke and which has 25,000 members living in the district. One political consultant, Scott Levenson, said a high union turnout could trump Mr. Yassky’s cash advantage and put Ms. Clarke over the top in a close race tomorrow.

The latest poll shows the four candidates in a statistical dead heat, with as many as one in five voters undecided.

Mr. Owens has been the most aggressive candidate in criticizing his opponents, and he stuck to that strategy in an interview yesterday. He said he was telling voters that he was the only candidate who was completely opposed to the Atlantic Yards project, and that he was the “only one who could beat David Yassky.” Of Ms. Clarke, he said: “Yvette doesn’t have the organization. Yvette is damaged goods, politically.”

Mr. Owens held a fund-raiser at his brother Millard’s home last night, and, perhaps seeking a celebrity boost, he planned to go door-to-door in the district with his other brother, Geoffrey, who played the character of Elvin in “The Cosby Show.”

Mr. Andrews, meanwhile, placed his emphasis less on the issues and more on reminding voters of his history in the district, much of which overlaps with his state Senate district. “I’m going to tell people that my birthday was on Saturday, and the best present they could give me is to put an X next to my name,” he said in an interview yesterday. Over the weekend, he campaigned with his big-name supporters, including Mr. Spitzer, the Reverend Al Sharpton, and Governor Cuomo.

For all four hopefuls, today is expected to be a quiet day, as none want to be seen as politicizing the September 11 attacks. Mr. Yassky had no public events scheduled, while the others planned to attend memorial services. Mr. Owens said he may stump at a subway stop in the morning, and Mr. Andrews said he would not campaign openly, but would be visible in his neighborhood. “I may do laundry,” he said. “Or I might go grocery shopping.”