Last week Fernando Ferrer, who has led the pack of four Democratic mayoral hopefuls since the beginning of the race, expressed frustration with the runoff system, which dashed his hopes four years ago and could do the same this year.

“I think it hasn’t helped the party. I think you’ve seen situations over the course of time, from 1973 going forward, when we’ve had runoffs that have been very hurtful,” he opined last Wednesday on the WB11 Morning News. They may have been hurtful to Mr. Ferrer, who was defeated in the 2001 runoff by the runner-up in the primary, Mark Green, but they certainly worked fine for Mayors Beame and Koch, two of the three Democrats who have occupied City Hall since the system began in 1973. David Dinkins passed the 40% threshold in 1989 to become the Democratic nominee without a runoff.

This is not the first time that the idea of a runoff has been challenged. In 1997, Reverend Al Sharpton, then running for mayor, expressed similar beliefs, going so far as to call the runoff system a “Dixiecrat trick” and vowing to challenge it in court. By the end of the campaign that year, Rev. Sharpton was singing a different tune, finally heading to court not to kill the system, but to try to force his inclusion in a runoff with Ruth Messinger, who barely achieved the 40% threshold.

Two days after Mr. Ferrer made his remarks, the WNBC/Marist College poll found that a surging Rep. Anthony Weiner had achieved a statistical dead heat with Mr. Ferrer. If the congressman’s momentum continues, it is conceivable that it would be Mr. Weiner, not Mr. Ferrer, who would garner the most votes tomorrow but still fall short of 40%.

In that case, I wonder whether Mr. Ferrer would generously offer to spare the city the expense of conducting the “hurtful” runoff and concede defeat, allowing Mr. Weiner to begin his stretch run against Mayor Bloomberg. In such a situation I suspect that like Rev. Sharpton eight years aho, Mr. Ferrer will become a convert to the runoff mechanism.

Reading the polls that show Mr. Ferrer’s numbers short of the 40% threshold and not moving, Rev. Sharpton moved quickly this weekend to assume the role of Democratic Party kingmaker. He finally endorsed the former Bronx president, whom he supported four years ago. Rev. Sharpton hopes to nudge Mr. Ferrer over the top – and get full credit for it.

Rev. Sharpton expressed dismay over the surging candidacy of Mr. Weiner, suggesting that the congressman’s initial vote supporting the Iraq war was a departure from Democratic orthodoxy that Rev. Sharpton, as self-appointed enforcer of party values, cannot tolerate. Never mind that Mr. Weiner voted the same way as Senators Clinton and Schumer, who I guess are also Democratic apostates.

Rev. Sharpton has long demonstrated his total commitment to the party and its values through the assistance he has provided in recent years to such kindred souls as Senator D’Amato, Governor Pataki, and even a jailed state senator, Guy Velella. And, of course, Messrs. Sharpton and Ferrer performed a selfless demonstration of party loyalty in the mayoral election four years ago.

***

When the four Democratic rivals were asked which of their fellow candidates “would you like to vote for if you couldn’t vote for yourself?” during last Wednesday’s debate, only one of the four named one.

That was Rep. Anthony Weiner, whose brightening prospects gave him a good strategic reason to offer an answer. Mr. Weiner said he would cast his vote for the Manhattan president, C. Virginia Fields. Should Mr. Weiner win a spot in a Democratic runoff he certainly would want Ms. Fields’s endorsement, as would the other presumed finalist, Fernando Ferrer. But only Mr. Weiner had the presence of mind to use the opportunity to court Ms. Fields.

Months ago, Mr. Ferrer made an early attempt to establish positive relations with Ms. Fields over a cup of coffee in a Bronx diner. They agreed on a “non-aggression pact.” But Ms. Fields’s ill-advised acceptance of the idea fell by the wayside when Mr. Ferrer made his Diallo gaffe last March. Smelling blood, Ms. Fields went after the former Bronx president on the issue, and she gained momentum at his expense.

My suspicion is that ultimately she will endorse Mr. Ferrer, as will the City Council speaker, Gifford Miller. That’s because the conventional wisdom – today – is that an ultimate Ferrer victory for the nomination is inevitable. But Mr. Weiner’s dramatic rise in the polls may change the calculus, particularly if new polls show that he has a better shot at defeating Mayor Bloomberg than Mr. Ferrer.