"If you had a race horse that won 43 races, brings in the money, but the horse is old and experienced and knows the track -- what would you do?" Rep. Charles Rangel said to reporters. "Would you send him to the glue factory? Hell no."

Rangel avoided the glue factory Tuesday evening in the Democratic primary in New York's 13th District, according to NY1 News. However, his opponent, state Senator Adriano Espaillat, said the race was too close to call and refused to concede, reports said Tuesday night.

Rangel was facing one of the most challenging races of his long political life Tuesday. In the 2012 Democratic primary, he beat Espaillat by only 1,000 votes. His prospects didn't look much better this time around.

And in many New York City political districts -- including the predominantly blue 13th -- the winner of the Democratic primary is expected to cruise to victory in the general election, so Tuesday's contest likely determined who will hold the seat. 

The powerful 84-year-old Rangel has held his seat in the U.S. House of Representatives for 22 terms, but Espaillat, 59, garnered the support and endorsement of new politicians and blocs that hadn't backed him two years ago, when he nearly unseated the mighty Rangel.

Rangel has been the political face of Harlem for years, and as a black man he represented the long-standing racial makeup of the history-rich neighborhood. But his 13th District is now 46 percent Hispanic, 34 percent black, 17 percent while and 3 percent Asian, according to an April report by the National Institute for Hispanic Policy -- a result of both a recent redistricting and changing times.

Espaillat would have been the first Dominican-American to be elected to the U.S. Congress.

The race was always expected to be a close one, though a late May New York Times/NY1/Siena College Poll had Rangel beating Espaillat by 41 percent to 32 percent, while lesser-known challengers Pastor Michael Walrond and Yolanda Garcia notched 6 percent and 5 percent, respectively.

Rangel has weathered many controversies and scandals during his time in office. In 2010, he stepped down from his prominent post as chairman of the House Ways and Means Committee. The move came as he attempted to contain damage to his reputation following ethical violations -- trips that were paid for by corporations -- that led to censure by the House Ethics Committee.

He has been a target for unseating by both Republicans and many Democrats in the years since. President Barack Obama declined to back him in 2010, 2012 and this year, but he was still able to win the support of President Bill Clinton, Sens. Charles Schumer and Kirsten Gillibrand and Gov. Andrew Cuomo during this year's campaign. New York City Mayor de Blasio did not take sides in the high-profile race.

Espaillat was not widely backed nationally, but he secured the endorsements of prominent city-level figures like Comptroller Scott Stringer and City Council Speaker Melissa Mark-Viverito.

The state Senator hit Rangel hard on what he sees as his inability to lead following his 2010 scandal. "After his censure, he hasn’t been able to pass legislation and he’s been ineffective," he said to CBS Local New York, which also reported that he was "very confident" that "we’re going to win comfortably."

Rangel found himself mired in controversy once again during a TV debate earlier this year, when he said, "Just what the heck has he actually done besides saying he’s a Dominican?"

His comments drew criticism from both Espaillat and de Blasio, who scolded him for resorting to what they and many others saw as political race-baiting.

Walrond, a pastor at First Corinthian Baptist Church and friend of Al Sharpton was a third, lesser-known, candidate; Garcia, a little-known Bronx community organizer born in the Dominican Republic, was a late entrance into the race, only declaring her candidacy in April.