As D.C. Mayor Vincent Gray gets ready to defend his job in the April 1 Democratic primary, PostTV looks at the highlights and low moments of his administration. (Theresa Poulson/The Washington Post)

The measure of a person’s character, we are often told, is best taken when he is under pressure, his back against the wall. A test of Vincent C. Gray’s moral core occurred in 2010, when he entered the D.C. mayoral race against a formidable incumbent. If the allegations made by prosecutors in court this week are true, Gray failed his test of character miserably, proving to be someone of such dubious integrity that he was willing to pursue an anti-democratic scheme straight out of the political narrative of some Third World dictatorship.

Where is Jimmy Carter when you need him? It’s too late for a do-over. But the corruption that permeated Gray’s 2010 campaign should disqualify him from elective office.

Tell me I am not the only D.C. resident who is tired of snake-oil sellers promising to usher in a new day only to catapult the city into yet another nightmare. Gray promised integrity and character. Who out there thinks we won’t soon be adding his name to the list of imposters?

On Monday, millionaire businessman Jeffrey E. Thompson said in open court that he financed — and that Gray participated in — an illegal, off-the-books, “shadow campaign” in 2010. That operation was designed to ensure Gray’s victory over incumbent Adrian Fenty while protecting Thompson’s array of D.C. government contracts.

Actually, even before Gray announced his candidacy, Thompson said, he promised the then-D.C. Council chairman that he would provide cash to the campaign but that he wanted his involvement to be kept secret. To seal the conspiracy, he said, Gray agreed to call Thompson “Uncle Earl.”

Later, Gray allegedly realized that he needed more money than anticipated for his get-out-the-vote effort, so his friend and political ally Vernon Hawkins went to Thompson to request another $425,000, according to court documents. Clearly understanding how to put a politician in a vise, Thompson said he demanded a face-to-face meeting with the candidate. Gray allegedly complied, presenting a one-page budget to Thompson as they sat for a meal at Jeanne Clarke Harris’s apartment. Thompson said he would provide the required cash but reminded the candidate about keeping everything hush-hush. Gray called Thompson “Uncle” as they left the meeting, Thompson said.

And now rich Uncle Earl, whom prosecutors said forked over nearly $700,000 to purchase the 2010 mayoral election for Gray, has suddenly become a liar: “Lies. These are lies,” said the mayor. It’s yet another sad example of the disintegration of the American family.

But is Thompson a liar? Gray wants residents to enter a netherworld of exquisitely parsed words. He admitted to WJLA-TV’s Sam Ford this week that he did meet Thompson at Harris’s home, but it wasn’t about getting money for the shadow campaign. Gray said Thompson merely “wanted to know how the campaign was going.”

Further, Gray said that he agreed to use the nickname because he sensed that Thompson didn’t want it known he was raising money. Why was Gray willing to go along with an effort to conceal information that local laws require be made public? The mayor also told NBC4’s Tom Sherwood that “I’m sure there are no documents that will corroborate my involvement in the [shadow campaign].” Is that because, as Gray knows, Thompson and others destroyed documents after U.S. Attorney Ronald C. Machen Jr. announced the launch of his investigation?

To be fair, Gray isn’t the only politician implicated in these recently disclosed campaign violations. Machen and his anti-corruption posse have promised to get them all.

D.C. Council Chairman Phil Mendelson, a so-called good-government advocate, has suggested that his colleagues, particularly those challenging Gray, muzzle themselves. Are there no defenders of democracy in this city?

Based on revelations of Gray’s alleged post-election actions, another investigation should be opened. Thompson said Gray’s team asked him for $60,000: $10,000 for a relative; $40,000 to repair the home of a “close personal” friend of Gray’s; and $10,000 for a labor-union candidate’s campaign.

If true, that’s nauseatingly sleazy. And if such requests were made on Gray’s behalf, it was against the law. A government official cannot solicit a gift from someone doing business with the city, and Thompson was a government contractor. Council member Marion Barry (D-Ward 8) was fined more than $13,000 by the D.C. Board of Ethics and Government Accountability for similar behavior.

Determined, it seems, to ignore the magnitude of events, Gray held his annual “State of the District” address as scheduled Tuesday. He offered a vigorous defense of himself, asking residents, “Who do you believe: A greedy man attempting to save himself? Or me, a public servant who has dedicated his entire career to giving back to our communities?” Gray must have forgotten about his friends — Harris, Hawkins and former D.C. Council member Michael Brown — who have pleaded guilty to felonies and have been cooperating in the federal investigation.

Voters face a critical and defining moment. They can become apathetic or cynical about these events, believing themselves impotent against political corruption, or they can take control of their government, selecting in the upcoming April 1 Democratic primary an ethical candidate. Council members Muriel Bowser (Ward 4), Jack Evans (Ward 2) and Tommy Wells (Ward 6) seem the best options.

Wells has presented himself as the most ethical of the challengers. But his meager resources could reshape the primary as one between Bowser and Evans.

There certainly should be no place for Gray — despite his portrayals of himself as an innocent, the victim of his friends.

Can I hear an amen?