Rep. Charles Rangel is battling to extend his 44-year reign as the congressman from Harlem in a primary Tuesday, abandoned by former allies who say it's time for the once-powerful lawmaker to go, and facing an opponent who almost beat him two years ago.

State Sen. Adriano Espaillat is endorsed by several prominent officials who backed Rangel the last time, including City Council Speaker Melissa Mark-Viverito and Comptroller Scott Stringer. Espaillat is Dominican-born in a district where Hispanics outnumber blacks among eligible voters 45 percent to 33 percent since a 2012 redistricting.

Rangel edged Espaillat that year by less than 1,000 votes. Their acrimonious campaign this time has been marked by racially tinged rhetoric, which led Mayor Bill de Blasio and the Rev. Al Sharpton to warn against divisive appeals.

Rangel, 84, and Espaillat, 59, are the top contenders in the four-way Democratic primary. Also running are the Rev. Michael Walrond, 43, of Harlem and Bronx activist Yolanda Garcia, 64. There is no Republican to challenge the winner in November.

Rangel led Espaillat 47 percent to 34 percent in a NY1/Siena College poll released Thursday night, with 7 percent for Walrond and 4 percent for Garcia. The poll's margin of error was plus or minus 3.7 percentage points.

Rangel outraised Espaillat 2-to-1 between Jan. 1, 2013 and June 4, 2014, though they are close in cash on hand, federal campaign finance filings show.

Rangel's premiere endorsers include former President Bill Clinton, Sen. Charles Schumer and ex-Gov. David A. Paterson, but a newer generation of city leaders such as Mark-Viverito and Stringer side with Espaillat. So does the United Federation of Teachers, formerly in Rangel's corner. De Blasio, a past campaign manager for Rangel, is sitting the race out.

Rangel was a leading power in the House until a 2010 censure for ethics violations cost him the Ways and Means Committee chairmanship.

Stringer paid homage to Rangel's decades of service as "extraordinary," but said the dean of New York's House delegation should make way for a successor who could serve deeper into the future to push causes such as immigration reform and health care.

"This is what the next 10 to 20 years is going to look like, and it weighs heavy on us to put someone in who's going to be there," Stringer said in an interview. "Sometimes, elections are about real change, and this is that moment."

Paterson said that "time and time again" on issues of housing, crime, education and jobs, "the person that was there with answers and solutions . . . was congressman Charles Rangel."

Asked by a reporter about ex-allies, Rangel said, "Do I understand politicians throwing someone under the bus because they got a long-range plan? I would say it's disappointing and sometimes surprising, but having had a great deal of ambition myself -- I guess."

Win or lose, many believe this year's re-election bid will be his last. Rangel wouldn't directly admit it, but gave a hint.

"My passion for politics has only been tempered by the fact that my wife and I intend to spend the rest of our nonpublic years enjoying what's left of life," he told reporters Tuesday in the Bronx.

At his birthday fundraiser June 5, Rangel said he has the strongest experience to help House Democrats against a Republican majority likely to remain intact in November and to "guide this ship into the dark for the next couple of years."

Harlem's status as a power center for black politicians has ebbed, said Harlem-based Democratic consultant Basil Smikle. Rangel's 13th District now includes Washington Heights, where Espaillat and a large Dominican population live; East Harlem, a Puerto Rican enclave; and parts of the Bronx.

The subject of identity rose to the surface in a June 6 debate. Rangel, who is black and Puerto Rican, cited a flier from Espaillat's 2012 campaign slamming a fellow Dominican legislator who backed Rangel as a betrayer of his community. Rangel also said of Espaillat, "What the heck has he done, besides saying he's a Dominican?"

The admonishments from de Blasio and Sharpton followed.

Stumping Tuesday in the Bronx, Espaillat placed less emphasis on the fact that he would be the first Dominican congressman and said he has grown since 2012. "There's always been a level of pride in being the first, but I want to be the best," he said in an interview. Growth means being "more inclusive and obviously, more accepting and more tolerant," he said.

Neither of the other candidates have legislative experience. Walrond, pastor of the 9,000-member First Corinthian Baptist Church in Harlem, was raised in Freeport and moved to Harlem in January. Garcia, a Dominican-born community activist, speaks limited English and has not participated in the debates.