The Department of Justice (DOJ) was reported this week to have begun a criminal investigation of former President Donald Trump in connection with his effort to contest the 2020 election.

Also this week, the DOJ was accused of having spiked its own investigation of President Joe Biden’s son, Hunter Biden, based on false clams that reports of his misconduct were just “disinformation.” And last week, the DOJ convinced a D.C. jury to convict Stephen K. Bannon, a Trump associate and former Breitbart News executive chairman, for contempt of Congress.

Notably, the DOJ declined to prosecute past left-wing offenders for the same crime — such as Lois Lerner, the former IRS official who targeted conservative groups; and former Attorney General Eric Holder, who refused to provide Congress with information about Operation Fast & Furious, a gunrunning fiasco that led to the murder of Border Patrol Agent Brian Terry.

And few at DOJ were punished for the “Russia collusion” hoax, a partisan operation that involved lying to the FISA court.

We are witnessing the transformation of the DOJ into an arm of the Democratic Party.

There have always been a few partisan prosecutors, but the political corruption began in earnest under President Barack Obama, who declined to prosecute members of the New Black Panther Party for voter intimidation; gave millions of dollars to left-wing groups from DOJ fines; and imposed DOJ consent decrees on police in Democrat-run cities to appease Black Lives Matter.

In 2016, the DOJ attempted to influence the presidential election in several ways — first, by declining to prosecute former Secretary of State Hillary Clinton in open-and-shut cases of mishandling classified information; second, by investigating Trump for “Russia collusion”; and third, by trying to sanitize the anticipated Hillary Clinton presidency by reopening the inquiry into her emails — a move that backfired spectacularly.

The “Russia collusion” probe continued into the Trump era, fueling efforts to undo the results of a democratic election, and arguably denting Trump’s ability to conduct foreign policy.

Throughout the left-wing riots that gripped the country in 2020, the DOJ was remarkably passive. Attorney General William Barr directed law enforcement on the streets of D.C. as Black Lives Matter and Antifa attacked the White House, but FBI Director Christopher Wray led efforts to deny that Antifa was a threat, insisting it was an “ideology,” not an organization.

The DOJ seemed to shrug at the riots that raged in 48 out of 50 major U.S. cities. And it dithered for years after Hunter Biden’s influence-peddling came to light. The FBI did nothing about his laptop, which it seemed to have seized in 2019 to cover up the story rather than to follow up on evidence of corruption at the highest level.

But after the Capitol riot on January 6, 2021, the DOJ prosecuted participants aggressively even for minor offenses, and detained non-violent suspects for months.

Now comes the news that Trump is being investigated by the DOJ in connection with January 6 — reportedly for “seditious conspiracy and conspiracy to obstruct a government proceeding” and “potential fraud associated with the false-electors scheme” or efforts to pressure officials to claim the election was fraudulent.

The timing of the news gave undue legitimacy to the January 6 Committee, a one-sided, arguably unlawful and unconstitutional show trial with obvious political motivations.

The DOJ inquiry is supposedly independent of the January 6 Committee, but there have already been reports that the DOJ has asked the Committee to hand over transcripts of witness depositions — given behind closed doors, and with few of the basic protections they would ordinarily have in a criminal inquiry.

In effect, the DOJ appears to have deputized the committee to carry out its own law enforcement functions — a violation of the Constitution’s separation of powers and the Bill of Rights.

After months of investigation, and more than 1,000 witnesses, the committee turned up nothing on Trump except the claim that he should have done more, or acted sooner, to stop the riot.

Trump did what many of the Democrats on the committee had done themselves: oppose the certification of electors from states where the results were controversial. He also organized a protest to influence a Congressional vote — an activity guaranteed by the protections of the First Amendment.

Notably, the DOJ is declining to prosecute the left-wing protesters who have besieged the homes of conservative Supreme Court justices in an effort to pressure them on the abortion issue — despite a specific federal law barring such protests as an exception to the First Amendment because they represent a threat to impartial justice and an independent judiciary.

The DOJ’s indulgence was followed by an attempt on the life of Justice Brett Kavanaugh by a leftist who, luckily, called 911 on himself.

Both President Biden and Attorney General Merrick Garland promised to “depoliticize” the DOJ, referring to the bogus claims by Democrats that Trump “politicized” it because Barr would not break federal law and hand over grand jury materials to Democrats desperate to smear Trump.

It was Trump, actually, who depoliticized the DOJ — or tried to, though he ran into the resistance of careerists and holdovers who were willing to break the law in their effort to undermine his presidency.

Garland told NBC News that the DOJ would not hesitate to prosecute Trump even if he were a candidate for president in 2024. That is the right policy — though the DOJ did not apply it to Hillary Clinton or Joe Biden. Worse, it followed Hillary Clinton’s lead in smearing and spying on her opponent, and covered up legitimate questions about Biden’s conflicts of interest. To this day, the perpetrators of the “Russia collusion” hoax remain unpunished for what was, in effect, a silent coup attempt.

Now the DOJ is apparently trying to find a way to put Trump behind bars, and satisfy the Democrats’ lust for revenge for 2016. This is what happens in Third World countries.

I witnessed it happening in my native South Africa, where the ruling clique began using petty investigations to discredit the opposition and internal rivals. Today, South Africa is on the verge of being a failed state.

The political corruption of the DOJ is likewise undermining faith in the rule of law; it must be stopped.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News and the host of Breitbart News Sunday on Sirius XM Patriot on Sunday evenings from 7 p.m. to 10 p.m. ET (4 p.m. to 7 p.m. PT). He is the author of the recent e-book, Neither Free nor Fair: The 2020 U.S. Presidential Election. His recent book, RED NOVEMBER, tells the story of the 2020 Democratic presidential primary from a conservative perspective. He is a winner of the 2018 Robert Novak Journalism Alumni Fellowship. Follow him on Twitter at @joelpollak.