The 2014 D.C. Democratic primary is likely to be the last hurrah for Mayor Vincent C. Gray. It may not, however, be his crowning glory.

Gray, 71 , is unlikely to have the last word. That may fall to U.S. Attorney Ronald C. Machen or to voters, neither of whom is expected to be kind.

Machen has made clear that his probe into Gray’s 2010 campaign will proceed, notwithstanding the upcoming elections. So Gray will get a pass only if federal prosecutors conclude after a two-year investigation that they haven’t amassed enough evidence to convict him in court.

If prosecutors give up, that still won’t represent a signal achievement for Gray.

If Gray wins the April 1 primary — and that’s not a given — he may garner only a plurality of the vote among the crowded field. Drawing 30 percent to 35 percent would be a victory but not a good outcome. It would mean a majority of Democrats who entered polling booths chose not to vote for the incumbent mayor, which would spell trouble for the general election.

Unifying Democratic backers of mayoral candidates Tommy Wells (Ward 6), Muriel Bowser (Ward 4), Jack Evans (Ward 2) and Vincent B. Orange (At Large) behind a Gray candidacy will be a tall order, especially if an alternative, and proven vote-getter, such as David Catania (I-At Large) is on the ballot in November.

Lest we forget, non-Democrats have won citywide races before.

Recall council member William Lightfoot (I-At Large), who was in office from 1989 to 1997; Hilda “Grandmother to the World” Mason (Statehood-At Large), from 1977 to 1999 ; Julius Hobson (Statehood-At Large), from 1975 to 1977; Carol Schwartz (R-At Large), from 1985 to 1989 and then 1997 to 2009 ; and former Democrat turned independent — and soon to be jailed — council member Michael Brown.

Next year may go down as Gray’s final performance in a career of public service that began in 1991, the year he and I first met.

The meeting took place on a chilly spring morning at the wind-swept Cedar Knoll Youth Detention Center in Laurel. Newly inaugurated D.C. Mayor Sharon Pratt Kelly named Gray director of the Department of Human Services, the huge bureaucracy that managed the city’s social service agencies and three youth detention centers.

We spent a good part of that day touring the dilapidated Cedar Knoll facility and the other two dismal centers, Oak Hill, also in Laurel, and the Receiving Home in Northeast Washington.

Gray had his hands full.

A November 1993 report by the Washington Legal Clinic for the Homeless catalogued the disaster that the Kelly administration and Gray had inherited from three-term mayor Marion Barry (D):

●District-funded shelters in which individuals and families lived, needlessly, among rats, lice and scabies; in beds with unwashed blankets stained from human excrement and blood and pus from open sores; and with clogged toilets that backed up into living areas;

●Hundreds of unoccupied D.C.-operated housing units standing empty as families needlessly spent winter nights in the freezing cold;

●Homeless children who could not get to public schools because the District refused to provide the required transportation;

●Food stamps and Medicaid benefits improperly withheld from poor families and children hungry and suffering from life-threatening diseases;

●Children shelved for years in the District’s foster-care system and in juvenile detention facilities crawling with snakes and vermin;

●Prisons that, because of negligent administration, had become breeding grounds for drug abuse, tuberculosis, AIDS and hepatitis.

Collapsed social services, dehumanizing and degrading treatment of vulnerable citizens; all damnable conditions repeatedly criticized in Post editorials — many written by me.

It is from that vantage point that I view Vince Gray’s 20-plus years of public service.

Gray, supported by Kelly, tried hard in those four years but largely failed to undo all the damage caused by Barry’s 12 years of maladministration. The Kelly administration’s hands were tied by court orders and an inherited workforce that was — to be charitable — dysfunctional.

But he helped lay the groundwork for subsequent reforms in human services that were implemented ably by mayors Tony Williams and Adrian Fenty.

Gray also earned passing grades as a legislator, ascending from Ward 7 council member to council chairman. He herded cats, but not as well as the late D.C. Council chairman John A. Wilson or Charlene Drew Jarvis, who briefly steered the council after chairman David A. Clarke died.

What was not so evident on that long-ago morning at Cedar Knoll was Gray’s desire for power and the headiness of high office.

It may have been there all along, that desire to win at all costs.

In 2010, Gray sat at the helm of a campaign team willing to cheat to win. And instead of taking responsibility for the things his team did, he now wants to say nothing about it.

That he cannot grasp the enormity of that offense is a sad last act. It is also disqualifying for future service.

Read more from Colbert King’s archive.