For 30 years, Jose E. Serrano, 75, has represented the beleaguered South Bronx. Serrano, perhaps the lowest-profile member of the city’s congressional delegation, was famous for boasting that he represented the nation’s poorest district — a feature he did nothing to fix in three decades.

Now he’s retiring, and the race to replace him may end up being the craziest political race of 2020.

Let’s begin with the current frontrunner, Councilman Ruben Diaz Sr. A former state senator — he was the only member of the so-called “Gang of Four” not to go to prison — and Pentecostal minister, Rev. Diaz was recently stripped of his committee chairmanship after he claimed that the City Council is run by a cabal of homosexuals.

Though backed by a fervent socially conservative base, Diaz has a hard ceiling of support that will be hard to break through; thus it is to his advantage to have as many contenders splitting the progressive vote as possible. Fortunately for him, leftist Democrats are rushing to occupy that side of the ledger.

Former City Council Speaker Melissa Mark-Viverito is running to represent a Bronx constituency from her home in Spanish Harlem, though she insists that living “literally one stop from the district” is close enough.

Mark-Viverito is best known for her long advocacy for Puerto Rican independentista and convicted terrorist Oscar Lopez Rivera, whose bombing of Fraunces Tavern in 1975 killed four people. When Lopez Rivera was freed from prison by then-President Barack Obama, Mark-Viverito arranged for him to serve as the “National Freedom Hero” of the Puerto Rican Day Parade. “It is really great to stand in solidarity with him,” she gushed.

At least Mark-Viverito at one time represented part of the 15th Congressional District, which is more than can be said for Councilman Ydanis Rodriguez, whose Washington Heights and Inwood district is entirely in Manhattan. Rodriguez has had a colorful tenure in the council to say the least, advocating strongly for the livery-car companies whose owners are his biggest supporters and arranging for a political ally to hire his wife as a highly paid adviser in a field she knew nothing about.

In 2016, during the debate about how much money councilmembers should be paid, Rodriguez memorably complained that no amount could compensate him for the fact that he works “more than full-time,” going to local meetings, talking to constituents in restaurants, etc. Why, he wondered, isn’t he paid time and a half for all the overtime he puts in?

On Rodriguez’s official council website, we are told, his “efforts during the Occupy Wall Street protests were recognized when he garnered Time Magazine’s 2011 Person of the Year.”

The “Person of the Year” that year was “The Protestor,” and while Rodriguez’s picture was included — along with dozens of other protestors — in a portfolio of photos, at no point did Time indicate that he was the “Person of the Year.”

Assemblyman Michael Blake, who at least actually represents the South Bronx, is also running for Serrano’s seat. Blake, a rising star who serves as vice-chair of the DNC, made news in 2015 when he was hired by Hilltop Public Solutions, a national political consulting firm that has close ties to Mayor Bill de Blasio and his numerous fundraising operations. The spectacle of a sitting elected official working simultaneously as a lobbyist proved too jarring even for the topsy-turvy world of Albany, and Blake resigned his position. It has recently emerged that Blake’s “honorary co-chairmanship” of a youth leadership training group was, in fact, highly compensated; he also failed to report income he made working for a notorious debt-collection service.

Also in the mix: Chivona Newsome, co-founder of Black Lives Matter of Greater New York, and the Bronx Progressives’ Samelys Lopez, who is angling to make an AOC-style incursion on the field.

Expect millions of dollars to pour into this electoral whirligig from elite national donors in an all-out “Stop Diaz” campaign. But with so many candidates jockeying in a first-past-the-post system, this race will be a Bronx Battle Royale.

Seth Barron is associate editor of City Journal.