New York Congressman Charlie Rangel was an early and essential backer of Hillary Clinton’s campaign for president.

The support of the senior House Democrat was required if the senator from New York was to be able to run nationally with the assurance that her home turf was “locked up.” And Rangel, as the dean of New York’s Democratic House delegation, and a dominant player in the politics of Harlem for four decades, helped to do just that.

Along with the support of Georgia Congressman John Lewis, Rangel’s backing also gave Clinton credibility in the African-American community beyond New York. But, now, Lewis is wavering in his support for Clinton — suggesting to the New York Times that, after his Atlanta-area congressional district voted overwhelmingly for Barack Obama, he is likely to cast his superdelegate vote at the Democratic National Convention for the surging senator from Illinois.

When word came that Lewis and other African-American House members were starting to talk about “keeping faith” with their constituents and voting for the candidate who could be the first African-American nominee for president, I immediately checked the results from Rangel’s congressional district.

According to figures reported after the February 5 New York primary, Rangel’s Harlem-based 15th district voted rather comfortably for Clinton. The unofficial count with 100 percent of the votes supposedly tabulated was:

Clinton — 55,359 votes, 53 percent

Obama — 47,514 votes, 45 percent

That was close enough to create a 3-3 delegate split. But it was a clear Clinton win, and thus there would be no pressure on Rangel to vote the will of a congressional district that backed Obama.

Or so it seemed.

Now comes Saturday’s New York Times Metro Section report headlined: “Unofficial Tallies in City Understated Obama Vote.”

According to the paper:

“Black voters are heavily represented in the 94th Election District in Harlem’s 70th Assembly District. Yet according to the unofficial results from the New York Democratic primary last week, not a single vote in the district was cast for Senator Barack Obama.

That anomaly was not unique. In fact, a review by The New York Times of the unofficial results reported on primary night found about 80 election districts among the city’s 6,106 where Mr. Obama supposedly did not receive even one vote, including cases where he ran a respectable race in a nearby district.

City election officials this week said that their formal review of the results, which will not be completed for weeks, had confirmed some major discrepancies between the vote totals reported publicly — and unofficially — on primary night and the actual tally on hundreds of voting machines across the city.:

The Times adds this relevant information: “The 94th Election District in Harlem, for instance, sits within the Congressional district represented by Charles B. Rangel, an original supporter of Mrs. Clinton.”

No one is suggesting that Rangel did anything wrong. There are many explanations for why vote counts are off, and there are many players in the process — and Rangel is one of the more honorable of the lot.

What New Yorkers should be asking for, however, is a complete review of the results in New York City, with a heavy focus not just on the 80 election district where Obama supposedly received no votes but also on those where it appears that his vote was far below the level of support that he received in surrounding districts — and that might reasonably be expected.

Could there be another 8,000 votes for Obama in the 15th?

That’s a lot. But it is not beyond the realm of possibility that they exist.

No one, be they Clinton or Obama supporters, should question that every effort must be made to find every Obama vote in Harlem, along with “missing” Obama votes from other congressional districts in Manhattan and Brooklyn.

At issue may be a few more pledged delegates for Obama — no small matter in a close race for the nomination — and the broader question of how superdelegates who want to respect the sentiments of their constituents, a group that could include Rangel and several other House members from New York, cast their votes at this summer’s convention.